Let A and B be two sets such that : n (A) = 20, n (A ∪ B) = 42 and n (A ∩ B) = 4. Find
n (B – A)
n (B – A) = n (B) – n (A ∩ B)

= 26 –4

= 22.

Question

Let A and B be two sets such that : n (A) = 20, n (A ∪ B) = 42 and n (A ∩ B) = 4. Find n (B – A)

Philoid · Accepted Answer

n (B – A) = n (B) – n (A ∩ B)

= 26 –4

= 22.