In a primary school 70%of the boys n 55%of the girls can ride a bicycle.If a boy and a girl are chosen at random what is the probability that@both of them can ride a bicycle,b..neither of them can ride a bicycle

Answer 1

prob(boy can ride) = .7 <---- BR
prob(boy can't ride) = .3 <--- BN
prob(girl can ride) = .55 <--- GR
prob(girl can't ride) = .45 <---GN

so we have 4 cases:
BR GR = (.7)(.55) = .385
BR GN = (.7)(.45) = .315
BN GR = (.3)(.55) = .165
BN GN = (.3)(.45) = .135 , notice they add up to 1

Now just pick which one suits your question.

Answer 2

The second question