In a class of 100 boys, 55 boys play football and 75 boys play rugby. Each boy must play at least one sport from football and rugby.
[3]
Find the number of boys who play both sports.
Write down the number of boys who play only rugby.
One boy is selected at random.[4]
Find the probability that he plays only one sport.
Given that the boy selected plays only one sport, find the probability that he plays rugby. Let A be the event that a boy plays football and B be the event that a boy plays rugby.
Explain why A and B are not mutually exclusive.[2]
Show that A and B are not independent.[3]