Agroup of 12 male and 8 female students is planning to go out for pizza. if 50% of the male students go and 25% of the female students go, find the probability that a random student who goes out for pizza is female.

12 male and 8 female...
50% of male students go0.50(12) = 6 of the males students go
25% of the females go0.25(8) = 2 female students go

the probability of a random student that is female going is :
females going / total people going = 
2 / (6 + 2) = 2/8 which reduces to 1/4 or 0.25 or 25% <==