Answer:
n=10, CF=59, FE=49
That would be choice 2. One acute angle is the complement of the other
eg in a 90-60-30 triangle sine 30 = cos 60
if 3/5 are boys
1- 3/5
5/5 -3/5 = 2/5 are girls
2/5 * 30 = 60/5 = 12
12 are girls
