1. P and Q are two sets. If n(P∪Q)=45 and n(P)=25 and n(Q)=35, then n(P∩Q) is
A) 10
B) 12
C) 20
D) 15

2. If I is the set of positive integers and P={x:x∈I, x^2<10 and x≠0},then
A) P = {0,1}
B) P = {0,1,2,3}
C) P = {1.2,3}
D) P is an infinite set

3. Simplify (1-y^2)/(y-y^2 )
A) 1/y
B) (1-y)/y
C) (1+y)/y
D) 1/(1-y)