Probability Stage 4 - Short Problems


This is part of our collection of Short Problems.

You may also be interested in our longer problems on Probability - Stage 4.


Printable worksheets containing selections of these problems are available here:

Stage 4 ★★ Sheet 1 Solutions

Two Girls

KS 4 Short Challenge Level:

Challenge Level:2 Challenge Level:2

Weekly Problem 45 - 2012
There are 10 girls in a mixed class. If two pupils are selected, the probability that they are both girls is 0.15. How many boys are in the class?

Pieces of Eight

KS 4 Short Challenge Level:

Challenge Level:2 Challenge Level:2

Weekly Problem 48 - 2014
Two of the triangles in the diagram are shaded black. What is the probability the resulting figure has at least one axis of symmetry?

Swapping Sweets

KS 4 Short Challenge Level:

Challenge Level:2 Challenge Level:2

If two girls each take a sweet from each other's bags, what is the probability that they end up with what they started with?

XOXOXO

KS 4 Short Challenge Level:

Challenge Level:2 Challenge Level:2

6 tiles are placed in a row. What is the probability that no two adjacent tiles have the same letter on them?

Domino Match

KS 4 Short Challenge Level:

Challenge Level:3 Challenge Level:3 Challenge Level:3

If you take two dominoes from a set at random, what is the probability that they 'match'?

Descending Deal

KS 4 Short Challenge Level:

Challenge Level:3 Challenge Level:3 Challenge Level:3

Weekly Problem 43 - 2012
Four cards from a set numbered 1-36 are dealt. What is the probability that they are dealt in order?