Apabila n(R)=25,n(R gabungan T)=40 dan n(R irisan T)=23.hitunglah n(T)

N(R) = 25
n(R u T) = n(R) + n(T) – n(R n T) = 40
n(R n T) = 23
Maka
n(R u T) = n(R) + n(T) – n(R n T)
40 = 25 + n(T) – 23
40 = 2 + n(T)
n(T) = 40-2 = 38