User interface language: English | Español

Date November Example question Marks available 2 Reference code EXN.1.AHL.TZ0.6
Level Additional Higher Level Paper Paper 1 Time zone Time zone 0
Command term Find Question number 6 Adapted from N/A

Question

The diagram below shows part of the screen from a weather forecasting website showing the data for town A. The percentages on the bottom row represent the likelihood of some rain during the hour leading up to the time given. For example there is a 69% chance (a probability of 0.69) of rain falling on any point in town A between 0900 and 1000.

Paula works at a building site in the area covered by this page of the website from 0900 to 1700. She has lunch from 1300 to 1400.

In the following parts you may assume all probabilities are independent.

Paula needs to work outside between 1000 and 1300 and will also spend her lunchtime outside.

Write down the probability it rains during Paula’s lunch break.

[1]
a.

Find the probability it will not rain while Paula is outside.

[2]
b.

Find the probability it will rain at least once while Paula is outside.

[2]
c.

Given it rains at least once while Paula is outside find the probability that it rains during her lunch hour.

[3]
d.

Markscheme

* This sample question was produced by experienced DP mathematics senior examiners to aid teachers in preparing for external assessment in the new MAA course. There may be minor differences in formatting compared to formal exam papers.

Note: Accept probabilities written as percentages throughout.

 

0.27        A1

 

[1 mark]

a.

Note: Accept probabilities written as percentages throughout.

 

0.22×0.28×0.52×0.73        (M1)

=0.0234 (0.02338336)        A1

 

[2 marks]

b.

Note: Accept probabilities written as percentages throughout.

 

10.02338336        (M1)

=0.977 (0.97661664)        A1

 

[2 marks]

c.

Note: Accept probabilities written as percentages throughout.

 

Prains during lunch  rains at least once=Prains during lunchPrains at least once        M1A1

0.270.97661664=0.276 0.276464        A1

 

[3 marks]

d.

Examiners report

[N/A]
a.
[N/A]
b.
[N/A]
c.
[N/A]
d.

Syllabus sections

Topic 4—Statistics and probability » SL 4.6—Combined, mutually exclusive, conditional, independence, prob diagrams
Show 306 related questions
Topic 4—Statistics and probability

View options