Date | May 2019 | Marks available | 2 | Reference code | 19M.1.SL.TZ2.T_13 |
Level | Standard Level | Paper | Paper 1 (with calculator from previous syllabus) | Time zone | Time zone 2 |
Command term | Find and Justify | Question number | T_13 | Adapted from | N/A |
Question
Little Green island originally had no turtles. After 55 turtles were introduced to the island, their population is modelled by
where is a constant and is the time in years since the turtles were introduced.
Find the value of .
Find the time, in years, for the population to decrease to 20 turtles.
There is a number beyond which the turtle population will not decrease.
Find the value of . Justify your answer.
Markscheme
* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.
(M1)
Note: Award (M1) for correct substitution of zero and 55 into the function.
45 (A1) (C2)
[2 marks]
(M1)
Note: Award (M1) for comparing correct expression involving 20 and their 45. Accept an equation.
(2.16992…) (A1)(ft) (C2)
Note: Follow through from their part (a), but only if positive.
Answer must be in years; do not accept months for the final (A1).
[2 marks]
10 (A1)
because as the number of years increases the number of turtles approaches 10 (R1) (C2)
Note: Award (R1) for a sketch with an asymptote at approximately ,
OR for table with values such as 10.003 and 10.001 for and , for example,
OR when approaches large numbers approaches 10. Do not award (A1)(R0).
[2 marks]
Examiners report
Syllabus sections
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19M.1.SL.TZ1.T_7a:
Place the numbers and in the correct position on the Venn diagram.
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19M.1.SL.TZ1.T_7b:
In the table indicate which two of the given statements are true by placing a tick (✔) in the right hand column.
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19M.1.SL.TZ2.T_1b:
Give your answer to part (a) correct to three significant figures.
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16N.1.SL.TZ0.T_1b:
Write your answer to part (a)
(i) correct to two decimal places;
(ii) correct to three significant figures.
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18N.1.SL.TZ0.T_1b:
Write down your answer to part (a) correct to the nearest integer.
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17M.2.SL.TZ1.T_4f:
In the context of this model, state what the value of 19 represents.
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18M.1.SL.TZ2.T_8b:
Calculate the area of the park.
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18N.1.SL.TZ0.T_9a.i:
Write down the value of x.
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19M.1.SL.TZ2.T_3b.i:
Calculate the amount, in DKK, that will be left to exchange after commission.
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18N.2.SL.TZ0.T_1a.ii:
Use your graphic display calculator to write down , the mean examination score.
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18N.2.SL.TZ0.T_1c.i:
Use the regression line y on x to estimate Jerome’s examination score.
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19M.2.SL.TZ1.T_5a:
Calculate, in CAD, the total amount John pays for the bicycle.
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17M.2.SL.TZ1.T_4c:
Find the value of .
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18N.1.SL.TZ0.T_3a:
Calculate the amount of MXN Harry received.
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17M.2.SL.TZ1.T_1b.i:
For the data from these seven species calculate , the Pearson’s product–moment correlation coefficient;
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17N.1.SL.TZ0.T_8a:
Use this exchange rate to calculate the amount of ARS that is equal to 350 AUD.
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18N.2.SL.TZ0.T_1a.iii:
Use your graphic display calculator to write down r , Pearson’s product–moment correlation coefficient.
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17N.2.SL.TZ0.T_3c:
Find the area of ABCD.
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18N.1.SL.TZ0.T_3b:
Calculate the value of the commission, in MXN, that Harry paid.
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17M.2.SL.TZ1.T_1b.ii:
For the data from these seven species describe the correlation between the average body weight and the average weight of the brain.
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18M.1.SL.TZ2.T_8a:
Calculate the length of side AC in km.
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16N.1.SL.TZ0.T_8c:
Find the value of and the value of .
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21N.2.SL.TZ0.7b.iii:
Write down the minimum value of .
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21N.2.SL.TZ0.7c.ii:
Write down the minimum total cost for this journey.
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21N.2.SL.TZ0.7b.i:
Find an expression, in terms of for the travel time , from to , passing through .
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19M.2.SL.TZ1.T_2c:
Find the maximum number of complete panels that can be fitted to the whole roof.
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19M.1.SL.TZ2.T_7b:
Write down an equation for the perimeter of the garden in terms of .
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19M.1.SL.TZ2.T_7a:
Write down an expression for the width of the garden in terms of .
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19M.1.SL.TZ2.T_11b.i:
Write down the elements that belong to .
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18M.2.SL.TZ2.T_5c:
Giovanni adds a point D to his diagram, such that BD = 45 m, and another triangle is formed.
Find the angle of elevation of A from D.
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19M.2.SL.TZ2.T_3b:
Find the slant height of the cone-shaped container.
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17M.1.SL.TZ2.T_6b:
Write down the number of leaves with a length less than or equal to 8 cm.
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18N.1.SL.TZ0.T_1a:
Calculate the volume of this hemisphere in cm3.
Give your answer correct to one decimal place.
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17M.1.SL.TZ1.T_9b:
Find the slant height, , of the cone.
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17M.1.SL.TZ1.T_8b:
Calculate the amount of USD she receives.
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17M.1.SL.TZ2.T_8b:
Find the value of .
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17M.1.SL.TZ2.T_8a:
Find the amount of Euros that Claudia receives. Give your answer correct to two decimal places.
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17M.1.SL.TZ2.T_6a:
Write down the median length of these leaves.
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19M.1.SL.TZ2.T_13a:
Find the value of .
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19M.1.SL.TZ2.T_11a:
Write down the elements that belong to .
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17M.1.SL.TZ2.T_6c.ii:
Before measuring, the researcher estimated to be approximately 9.5 cm. Find the percentage error in her estimate.
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17M.2.SL.TZ1.T_4a:
Calculate the volume of this pan.
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21N.2.SL.TZ0.7a.ii:
the boat travels directly to .
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16N.2.SL.TZ0.T_6b:
Express this volume in .
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16N.2.SL.TZ0.T_6c:
Write down, in terms of and , an equation for the volume of this water container.
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16N.2.SL.TZ0.T_6e:
Find .
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16N.2.SL.TZ0.T_6f:
Using your answer to part (e), find the value of which minimizes .
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16N.1.SL.TZ0.T_8b:
Use the information about the cost of tickets to write down a second equation in and .
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18N.2.SL.TZ0.T_1a.i:
Use your graphic display calculator to write down , the mean project mark.
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19M.1.AHL.TZ1.H_8a:
Write down the -coordinate of the point of inflexion on the graph of .
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19M.1.SL.TZ2.T_11b.ii:
Write down .
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19M.1.SL.TZ2.T_1c:
Write your answer to part (b) in the form , where 1 ≤ < 10 , .
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18M.1.SL.TZ1.T_14a:
Calculate the radius of the base of the cone which has been removed.
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21M.3.AHL.TZ1.2b:
Write down, in terms of and , an expression for the area, , of one of these isosceles triangles.
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18M.1.SL.TZ2.T_15b:
The total external surface area of the pencil case rounded to 3 significant figures is 570 cm2.
Using your graphic display calculator, calculate the value of r.
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21M.3.AHL.TZ1.2a:
Find the side length, , where , of a square such that .
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18N.1.SL.TZ0.T_1c:
Write down your answer to part (b) in the form a × 10k , where 1 ≤ a < 10 and k ∈ .
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18N.1.SL.TZ0.T_3c:
The exchange rate for this exchange was 1 USD = 17.24 MXN.
Calculate the amount of USD Harry received. Give your answer correct to the nearest cent.
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18N.2.SL.TZ0.T_1b.i:
Find the exact value of m and of c for these data.
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19M.1.SL.TZ1.T_1c:
Find the volume, in cm3, of this calculator case.
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18N.1.SL.TZ0.T_9b:
1 cm3 of glass has a mass of 2.56 grams.
Calculate the mass, in grams, of the paperweight.
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16N.1.SL.TZ0.T_8a:
Use the above information to write down an equation in and .
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17N.1.SL.TZ0.T_8c:
Find the value of .
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19M.1.SL.TZ2.T_3a:
Calculate the amount that Velina receives in DKK.
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16N.1.SL.TZ0.T_8d:
Find the percentage error.
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17N.1.SL.TZ0.T_8b:
Calculate the total amount of ARS Jose paid to get 350 AUD.
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19M.1.SL.TZ2.T_1a:
Use this model to calculate the circumference of the Moon in kilometres. Give your full calculator display.
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16N.1.SL.TZ0.T_4b:
Calculate the total amount, in USD, that Javier has remaining from his 5000 USD after his trip to Venezuela.
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18M.1.SL.TZ2.T_15a:
Find an expression for the slant height of the cone in terms of r.
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16N.1.SL.TZ0.T_1a:
Calculate the value of . Write down your full calculator display.
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19M.2.SL.TZ2.T_2d:
The length of path AD is 287 m.
Find the area of the region ABCD.
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19M.1.SL.TZ2.T_3b.ii:
Hence, calculate the amount of USD she receives.
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19M.1.SL.TZ2.T_13b:
Find the time, in years, for the population to decrease to 20 turtles.
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18M.1.SL.TZ1.T_14b:
Calculate the curved surface area of the cone which has been removed.
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17M.2.SL.TZ1.T_4d:
Find the temperature that the pizza will be 5 minutes after it is taken out of the oven.
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16N.1.SL.TZ0.T_1c:
Write your answer to part (b)(ii) in the form , where .
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17M.1.SL.TZ1.T_9a:
Find the radius, , of the circular base of the cone.
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17M.1.SL.TZ1.T_9c:
Find the curved surface area of the cone.
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18M.1.SL.TZ1.T_14c:
Calculate the curved surface area of the remaining solid.
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19M.2.SL.TZ1.T_5e:
John purchased the bicycle in 2008.
Justify why John should not insure his bicycle in 2019.
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17M.1.SL.TZ2.T_6c.i:
Use the graph to find the value of .
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16N.1.SL.TZ0.T_4a:
Calculate the amount of VEF that Javier receives.
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19M.1.SL.TZ2.T_7c:
Find the value of .
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18N.2.SL.TZ0.T_1b.ii:
Show that the point M (, ) lies on the regression line y on x.
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16N.2.SL.TZ0.T_6d:
Show that .
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17N.1.SL.TZ0.T_3b:
Find the distance from the Earth to Polaris in millions of km. Give your answer in the form with and .
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16N.2.SL.TZ0.T_6g:
Find the value of this minimum area.
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18N.1.SL.TZ0.T_9a.ii:
Calculate the volume of the paperweight.
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17M.1.SL.TZ1.T_8a:
Calculate the amount of PEN she receives.
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17N.1.SL.TZ0.T_3a:
Calculate the time, in minutes, it takes for light from the Sun to reach the Earth.
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21N.2.SL.TZ0.7a.i:
the boat is taken from to , and the bus from to .
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21N.2.SL.TZ0.7b.ii:
Find the value of so that is a minimum.
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21N.2.SL.TZ0.7c.i:
Find the new value of so that the total cost to travel from to via is a minimum.
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18M.2.SL.TZ2.T_5a.i:
Use Giovanni’s diagram to show that angle ABC, the angle at which the Tower is leaning relative to the
horizontal, is 85° to the nearest degree. -
18M.2.SL.TZ2.T_5a.ii:
Use Giovanni's diagram to calculate the length of AX.
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18M.2.SL.TZ2.T_5a.iii:
Use Giovanni's diagram to find the length of BX, the horizontal displacement of the Tower.
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18M.2.SL.TZ2.T_5b:
Find the percentage error on Giovanni’s diagram.
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17N.2.SL.TZ0.T_3a:
Show that correct to the nearest metre.
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17N.2.SL.TZ0.T_3b:
Calculate angle .
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17N.2.SL.TZ0.T_3d.i:
Calculate Abdallah’s estimate for the area.
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17N.2.SL.TZ0.T_3d.ii:
Find the percentage error in Abdallah’s estimate.
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17M.2.SL.TZ1.T_1a:
Find the range of the average body weights for these seven species of mammal.
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17M.2.SL.TZ1.T_1c:
Write down the equation of the regression line on , in the form .
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17M.2.SL.TZ1.T_1d:
Use your regression line to estimate the average weight of the brain of grey wolves.
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17M.2.SL.TZ1.T_1e:
Find the percentage error in your estimate in part (d).
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17M.2.SL.TZ1.T_1f:
State whether it is valid to use the regression line to estimate the average weight of the brain of mice. Give a reason for your answer.
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19M.2.SL.TZ1.T_2a:
Find the length , giving your answer to four significant figures.
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19M.2.SL.TZ1.T_2b:
Find the total area of the two rectangles that make up the roof.
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19M.2.SL.TZ1.T_2d:
Find the percentage error in her estimate.
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19M.2.SL.TZ1.T_2e:
Olivia investigates arranging the panels, such that the longer edge of each panel is parallel to or .
State whether this new arrangement will allow Olivia to fit more solar panels to the roof. Justify your answer. -
18N.2.SL.TZ0.T_1c.ii:
Justify whether it is valid to use the regression line y on x to estimate Jerome’s examination score.
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18N.2.SL.TZ0.T_1d:
In his final IB examination Jerome scored 65.
Calculate the percentage error in Jerome’s estimated examination score.
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17M.2.SL.TZ1.T_4b:
Find the radius of the sphere in cm, correct to one decimal place.
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17M.2.SL.TZ1.T_4e:
Calculate, to the nearest second, the time since the pizza was taken out of the oven until it can be eaten.
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16N.2.SL.TZ0.T_6a:
Write down a formula for , the surface area to be coated.
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16N.2.SL.TZ0.T_6h:
Find the least number of cans of water-resistant material that will coat the area in part (g).
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19M.2.SL.TZ2.T_3c:
Show that the total surface area of the cone-shaped container is 314 cm2, correct to three significant figures.
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19M.2.SL.TZ2.T_3d:
Find the height, , of this cylinder-shaped container.
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19M.2.SL.TZ2.T_3a:
Find the volume of one cone-shaped container.
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19M.2.SL.TZ2.T_3e:
The factory director wants to increase the volume of coconut water sold per container.
State whether or not they should replace the cone-shaped containers with cylinder‑shaped containers. Justify your conclusion.
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19M.2.SL.TZ2.T_2a:
Find the distance from A to C.
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19M.2.SL.TZ2.T_2b.i:
Find the size of angle .
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19M.2.SL.TZ2.T_2b.ii:
Find the size of angle .
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19M.2.SL.TZ2.T_2c:
Find the size of angle .
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19M.2.SL.TZ1.T_5b:
Find the value of the bicycle during the 5th year. Give your answer to two decimal places.
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19M.2.SL.TZ1.T_5c:
Calculate, in years, when the bicycle value will be less than 50 USD.
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19M.2.SL.TZ1.T_5d:
Find the total amount John has paid to insure his bicycle for the first 5 years.