need help plz venn diagram

Fifty students in an Ottawa school were interviewed with the following results: 45 spoke French, 10 spoke Chinese, and 8 spoke both languages. (All 50 students spoke English.) Find the probability that a randomly selected student from this group:
a) speaks both French and Chinese;
b) speaks neither French nor Chinese (only English);
c) speaks only one of French or Chinese (along with English)

a)
A= peoplewho speak french
B= people who speak Chinese
C = people who speak english
P(AB) = 8/50 =0.16

b) 1- 45/50 - 10/50-8/50
1-27/50

Drawing a venn diagram helps with these problems.
http://i3.photobucket.com/albums/y79...4/untitled.jpg
a) Your answer is correct.
b) P(A'andB')= 1-(P(A)+P(B)-P(AandB))= 1-(45/50+10/50-8/50)= 1-(47/50)= 3/50= .06
c) P(A)+P(B)-2P(AandB)= 45/50+10/50-2(8/50)= 39/50= .78