Three new students are going to join Andy and Steven’s homeroom. They try to guess the

gender of the new students. Andy guesses 2 boys and 1 girl while Steven says they will all

be girls.

a Draw a tree diagram to show all the possibilities (sample space).

b What is the probability that Andy is correct?

c What is the probability that Steven is correct?

d What is the probability that both Andy and Steven are wrong?

e What is the probability that at least one of the new students is a boy?