Given: n(A) = 54, n(B) = 39, n(B – A) = 13
Using the hint
n(B) = n(B – A) + n(A ∩ B)
⇒ 39 = 13 + n(A ∩ B)
⇒ n(A ∩ B) = 39 – 13
⇒ n(A ∩ B) = 26
Visualizing the hint given,
Given: n(A) = 54, n(B) = 39, n(B – A) = 13
Using the hint
n(B) = n(B – A) + n(A ∩ B)
⇒ 39 = 13 + n(A ∩ B)
⇒ n(A ∩ B) = 39 – 13
⇒ n(A ∩ B) = 26
Visualizing the hint given,