IB Questionbank

User interface language: English | Español

Date	May 2013	Marks available	3	Reference code	13M.1.sl.TZ1.5
Level	SL only	Paper	1	Time zone	TZ1
Command term	Find	Question number	5	Adapted from	N/A

Question

The probability that Tanay eats lunch in the school cafeteria is $\frac{3}{5}$ .

If he eats lunch in the school cafeteria, the probability that he has a sandwich is $\frac{3}{{10}}$ .

If he does not eat lunch in the school cafeteria the probability that he has a sandwich is $\frac{9}{{10}}$ .

Complete the tree diagram below.

[3]

Find the probability that Tanay has a sandwich for his lunch.

[3]

Markscheme

(A1)(A1)(A1) (C3)

Note: Award (A1) for each correct pair of branches.

$\frac{3}{5} \times \frac{3}{{10}} + \frac{2}{5} \times \frac{9}{{10}}$ (A1)(ft)(M1)

Notes: Award (A1)(ft) for their two correct products, (M1) for addition of their products. Follow through from their tree diagram.

$= \frac{{27}}{{50}}(0.54,54\% )$ (A1)(ft) (C3)

Examiners report

[N/A]

Syllabus sections

Topic 3 - Logic, sets and probability » 3.7 » Probability of combined events, mutually exclusive events, independent events.

Show 100 related questions

18M.2.sl.TZ2.1e: Find $n\left( {\left( {C \cup B} \right) \cap P'} \right)$ .
18M.2.sl.TZ2.1d: Find the number of employees who, in the last year, did not travel to work by car, bicycle or...
18M.2.sl.TZ2.1c.ii: Find the value of y.
18M.2.sl.TZ2.1c.i: Find the value of x.
18M.2.sl.TZ2.1b.iii: Use the tree diagram to find the probability that an employee encountered traffic given that...
18M.2.sl.TZ2.1b.ii: Use the tree diagram to find the probability that an employee was late for work.
18M.2.sl.TZ2.1b.i: Use the tree diagram to find the probability that an employee encountered traffic and was...
18M.2.sl.TZ2.1a.ii: Write down the value of b.
18M.2.sl.TZ2.1a.i: Write down the value of a.
18M.1.sl.TZ2.7c: Two girls are selected at random. Calculate the probability that one girl answered questions...
18M.1.sl.TZ2.7b: Find the probability that the boy answered questions in Hindi.
18M.1.sl.TZ2.7a: State the number of boys who answered questions in Portuguese.
17N.2.sl.TZ0.4g: Estimate the number of employees, from this 38, who are allergic to nuts.
17N.2.sl.TZ0.4f: Find the probability that the tested adult is allergic to nuts given that the liquid turned...
17N.2.sl.TZ0.4e: Find the probability that the liquid turns blue.
17N.2.sl.TZ0.4d: Find the probability that this adult is allergic to nuts and the liquid turns blue.
17N.2.sl.TZ0.4c: Copy and complete the tree diagram.
17N.2.sl.TZ0.4b: Find the probability that both people chosen are not allergic to nuts.
17N.2.sl.TZ0.4a: Find the probability that this person is not allergic to nuts.
17N.1.sl.TZ0.7c: Determine whether the events $S$ and $M$ are independent.
17N.1.sl.TZ0.7b: One of the students who joined the sports club is chosen at random. Find the probability that...
17N.1.sl.TZ0.7a: Complete the Venn diagram for these students.
17M.1.sl.TZ2.10c: Write down an expression, in terms of $a$ , for the probability that at least one of...
17M.1.sl.TZ2.10b.ii: Find the probability that at least one of Francesco’s light bulbs is defective.
17M.1.sl.TZ2.10b.i: Find the probability that both light bulbs are not defective.
17M.1.sl.TZ2.10a: Write down the probability that a light bulb produced by Home Shine is not defective.
17M.1.sl.TZ1.2c: Write down your answer to part (b) in the form $a \times {10^k}$ where...
17M.1.sl.TZ1.2b: Calculate the number of people in Ottawa that speak both English and French.
17M.1.sl.TZ1.2a: Calculate the percentage of the population of Ottawa that speak English but not French.
16N.2.sl.TZ0.6f: Using your answer to part (e), find the value of $r$ which minimizes $A$ .
16N.2.sl.TZ0.2d: Find the probability that this person (i) went on at most one trip; (ii) went on...
16N.2.sl.TZ0.2c: Write down the value of $n(B \cap C)$ .
16N.2.sl.TZ0.2b: Show that $x = 3$ .
16N.2.sl.TZ0.2a: Draw a Venn diagram to represent the given information, using sets labelled $B$ , $C$ and...
16N.1.sl.TZ0.12b: Find the value of $p$ .
10M.1.sl.TZ1.8b: Find the probability that Maria is late for school.
10M.1.sl.TZ1.13b: Find the probability that a student chosen at random is either male or studies Chemistry.
10M.1.sl.TZ2.8a: Find ${\text{P}}(A \cap B)$ .
10M.1.sl.TZ2.8c: Decide whether A and B are independent events. Give a reason for your answer.
10N.1.sl.TZ0.6a: Write down the probability that this person is a smoker.
10N.1.sl.TZ0.6b: Write down the probability that this person is male given that they are a smoker.
10N.1.sl.TZ0.6c: Find the probability that this person is a smoker or is male.
10N.2.sl.TZ0.1A.f: Two students are chosen at random. Find the probability that both students had all three...
11N.1.sl.TZ0.10a: Write down the probability that (i) Ju Shen chooses a red disc from the bag; (ii) Ramón...
11N.1.sl.TZ0.10b: Find the probability that Ju Shen and Ramón choose different coloured discs from the bag.
12N.2.sl.TZ0.4a: Use the table to find the probability that (i) a television will be bought by a...
12N.2.sl.TZ0.2e: Two students are chosen at random from the 450 students. Calculate the probability that (i)...
12M.1.sl.TZ1.12b: Find the probability that Merryn will not be late for the concert.
10M.2.sl.TZ2.1c.i: Find the probability that he chooses a chocolate biscuit.
12M.2.sl.TZ1.2h: Two students are chosen at random from the 120 students. Find the probability that (i) both...
12M.2.sl.TZ2.1b: Leanne catches a fish. Find the probability that she (i) catches an undersized bream; (ii)...
12M.2.sl.TZ2.1d: Leanne notices that on windy days, the probability she catches a fish is 0.1 while on...
12M.2.sl.TZ2.1e: Leanne notices that on windy days, the probability she catches a fish is 0.1 while on...
12M.2.sl.TZ2.1f: Use your answer to part (e) to calculate the probability that Leanne catches a fish on two...
11N.2.sl.TZ0.2a: A student is chosen at random from the group. Find the probability that the student (i) ...
11N.2.sl.TZ0.2b: Pam believes that the Mathematics course a student chooses is independent of the language in...
09N.1.sl.TZ0.9b: Find the probability that it does not snow tomorrow and Chuck is late for school.
09N.1.sl.TZ0.9c: Find the probability that Chuck is late for school.
09N.1.sl.TZ0.14a: Draw a Venn diagram in the space below to illustrate this information.
11M.1.sl.TZ1.9b: Calculate the probability of rain tomorrow.
09M.1.sl.TZ1.11b: Find the probability that the difference between the two numbers shown on the dice is 1.
09M.1.sl.TZ1.11c: Find the probability that the number shown on the four-sided die is greater than the number...
09M.2.sl.TZ1.2i, b: Find the probability that Lisa cooks dinner and they do not have pasta.
11M.2.sl.TZ1.2B.b: One of the survey forms was chosen at random, find the probability that the form showed...
09M.1.sl.TZ2.10a: If events A and B are mutually exclusive, write down the value of ${\text{P}} (A\cap B)$ .
09M.1.sl.TZ2.10b: If events A and B are independent, find the value of ${\text{P}} (A\cap B)$ .
09M.1.sl.TZ2.10c: If ${\text{P}} (A \cup B) = \frac{7}{13}$ , find the value of ${\text{P}} (A \cap B)$ .
09M.1.sl.TZ2.13c: The die is now thrown twice. Calculate the probability that black appears on top both times.
11M.1.sl.TZ2.9a: One traveller is to be chosen at random from all those interviewed. Find the probability...
11M.1.sl.TZ2.9b: One female traveller is to be chosen at random from all those interviewed. Find the...
13M.2.sl.TZ1.2d: A student is chosen at random from the 100 that were asked above. Find the probability that...
13M.1.sl.TZ2.10b: Alan returns the sock to the laundry basket and selects two socks at random. Find the...
13M.1.sl.TZ2.10c: Alan returns the socks to the laundry basket and again selects two socks at random. Find the...
13M.2.sl.TZ2.1c: A family is chosen at random from the group of 40 families. Find the probability that the...
SPM.2.sl.TZ0.5d: Two students are chosen at random from all $50$ students. Find the probability that(i) ...
07M.2.sl.TZ0.5i.a: One of the dogs is chosen at random. (i) Find P (the dog is grey and has the yellow...
07M.2.sl.TZ0.5i.b: Neil often takes the dogs to the park after they have eaten. He has noticed that the grey dog...
07M.2.sl.TZ0.5ii.c: Two mice are chosen without replacement. Find P (both mice are short-tailed).
07N.2.sl.TZ0.1i.c: Find the probability that Geraldine is late.
08N.1.sl.TZ0.2d: One student is chosen at random from the group. Find the probability that this student...
08N.2.sl.TZ0.3c: Two drivers are chosen at random. Calculate the probability that (i) both wear a seat...
08M.2.sl.TZ1.2i.d: If two students are chosen at random, calculate the probability that they both own a cell...
08M.2.sl.TZ1.2ii.b: Calculate the probability that (i) Kate goes to the cinema and is not late; (ii) the...
08M.1.sl.TZ2.14b: Find the probability that Andy loses the point.
08M.2.sl.TZ2.2i.b: Two people are chosen at random from those surveyed. Find the probability that they both...
14M.2.sl.TZ2.1b: Calculate the probability that Tomek wears (i) shorts and no tie; (ii) no...
14M.2.sl.TZ2.1c: The conference lasts for two days. Calculate the probability that Tomek wears trousers on...
14M.2.sl.TZ2.1d: The conference lasts for two days. Calculate the probability that Tomek wears trousers on...
13N.1.sl.TZ0.7b: Find the probability that Ramzi buys a magazine when he travels to work.
13N.2.sl.TZ0.3e: Find the probability that a woman selected at random from the group had visited Europe.
13N.2.sl.TZ0.3g: Two women from the group are selected at random. Find the probability that both women...
14M.1.sl.TZ1.7b: Calculate the probability that it will snow tomorrow.
14M.2.sl.TZ1.2c: There were 25 tourists in the group and every tourist saw at least one of the three types of...
15M.1.sl.TZ1.8c: Aleph and Beth are each going to roll their die once only. Shin says the probability that...
15M.1.sl.TZ1.11b: For a different day, also chosen at random, find the probability that Peter cycled to work...
15M.2.sl.TZ2.1e: The number of customers that like only mangoes is equal to the number of customers that like...
15M.2.sl.TZ2.1f: The number of customers that like only mangoes is equal to the number of customers that like...
14N.2.sl.TZ0.2b: (i) Find the probability that Mike reaches Trap B. (ii) Find the probability that...
14N.2.sl.TZ0.2c: Sonya, a lab assistant, counts the number of paths that lead to traps or escape doors. She...
14N.2.sl.TZ0.2d: During the first trial Mike escapes. Given that Mike escaped, find the probability that he...

Hide related questions

Question

Markscheme

Examiners report

Syllabus sections

View options