Question

Let the Universal Set, S, have 140 elements. A and B are subsets of S. Set A contains 76 elements and Set B contains 16 elements. If the total number of elements in either A or B is 91, how many elements are in A but not in B?

Answer 1

Answer:

the number of elements are in A but not in B

n(A-B) = 75

Step-by-step explanation:

Given  universal set (S) = 140

also given A and B are subsets of 'S'

Given n(A) = 76 , n(B) =16 and n(AUB) =91

we have to find n(A-B) ?

we can use formula

n(A-B) = n(AUB)-n(B)

          = 91 - 16 =75

Final answer:-

the number of elements are in A but not in B

n(A-B) = 75