19 boys turn out for playing hockey. Of these, 11 are wearing hockey shirts and 14 are wearing hockey pants. There are no boys without shirts and pants. What is the number of boys wearing full uniform?
A (hockey shirts) = 11
B (hockey pants) = 14
A ∪ B (shirt or pant) = 19 (as no boys are without shirts and pants)
A ∩ B (both shirt and pant) = A + B - (A ∪ B)
= 11 + 14 - 19
The correct option is C.