I'm having a problem with probability. someone asap.

a first grade class of nine girls and seven boys walks into a class in alphabetical order (by last name). what is the probability that three girls are the first to enter the room? show your calculation.

(a) 0.15
(b) 0.20
(c) 0.35
(d) 0.45,

The total number of students in the class is 9 + 7 = 16 The probability first person is a girl is 9/16 The probability second person is a girl is 8/15 The probability third person is a girl is 7/14 The probability that three girls are the first to enter is 9/16 * 8/15 * 7/14 = 504/3360 = 0.15. Option A.