Skip to content

Course home

4.1 Probability (A-level only)

4.1 Probability (A-level only)

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145
Question 6

Two jars, J1 J_1\,J1​ and J2J_2J2​, contain blue, white, and black marbles. Jar J1 J_1\,J1​ contains 4 blue marbles, 3 white marbles, and 3 black marbles. Jar J2 J_2\,J2​ contains 2 blue marbles, 5 white marbles, and 1 black marble. Sam picks one marble at random from jar J1 J_1\,J1​ and places it into jar J2J_2J2​. Sam then picks one marble at random from jar J2J_2J2​.

a.

Draw a tree diagram to represent this information.

[2]
b.

Find the probability that Sam picks two marbles of the same colour.

[2]
c.

Given that both marbles are the same colour, find the probability they are both black.

[2]
Markscheme

4.1 Probability (A-level only) Questions

  1. A Level
  2. /Maths
  3. /4.1 Probability (A-level only)

164 exam-style questions on WJEC A Level Maths 4.1 Probability (A-level only), covering 4.1.1 Probability (A-level only), 4.1.2 Probability (A-level only), and 4.1.3 Probability (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

Question bank