I think is is (-6,1.5) correct me if i am wrong
B={x|x is an even whole no less than 9}
Now

There are 4 boys and 12 students in total. It would be 4/12, but if it was to be simplified, it would be 1/3. The probability of a boy being selected is 1/3.
Given that 24 hours is one full day, we can deduce that 2400 hours is 100 days. One full cycle from that time is equivalent to that time therefore, 2400 hours after 5pm is 5pm.