Answer :
7th grade has 3 boy out of 10 students
probability of picking a boy is 3/10
8th grade has 9 boys out of 12 students are boys
probability of picking a boy is 9/12 reduced to 3/4
3/10 x 3/4 = 9/40 probability of picking 2 boys
7th grade has 3 boy out of 10 students
probability of picking a boy is 3/10
8th grade has 9 boys out of 12 students are boys
probability of picking a boy is 9/12 reduced to 3/4
3/10 x 3/4 = 9/40 probability of picking 2 boys