In a group of 16 students, the probability of randomly selecting 2 girls in a row without replacing the names back is 1/12. how many girls are in the group?

The probability of selecting one girl from the group is where is the number of girls in the group. Without replacing her, the probability of selecting another girl from the group would be . Assuming selection is independent, this means



There are two solutions here, and . The number of girls in the group must be positive, so there must be 5 girls in the group.

The correct answer is $90