P = {3, 9, 11, 13} and Q = {3, 7, 9, 15} are subset of the universal set ξ = {1, 3, 7, 9, 11, 13, 15} find PI ∩ QI
A
{3, 9}
B
{5, 7, 9}
C
{1}
D
{1, 11}
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
PI = {1, 7, 15} ; QI = {1, 13, 11}
PI ∩ QI = {1}
Source: Myschool Past Questions Archive (Record #26699)