thephoenix wrote:Mr. Yutaro's class contains 5boys and 11 girls. If two students are chosen, one at a time, from the class, what is
the probability that a boy and a girl are chosen?
A. 9/48
B. 9/20
C. 11/24
D. 27/48
E. 13/16
No of ways in which 2 students can be chosen from the group of 16 (11+5) = 16C2 = 16*15/2 = 8*15 =120
No of ways in which 1 girl and 1 boy can be chosen from 11 girls and 5 boys = 11C1*5C1 = 55
[spoiler]
Probability = 55/120 = 11/24[/spoiler]
Always borrow money from a pessimist, he doesn't expect to be paid back.
