Question

Let S = {x : x is a positive multiple of 3 less than 100}, P = {x : x is a prime less than 20}. Then, n(S) + n(P) is
(a) 34
(b) 31
(c) 33
(d) 30

Answer 1

Let S = {x : x is a positive multiple of 3 less than 100}
P = {x : x is prime less than 20}
Here S = {3, 6, 9, 12, ........99}
n(S) = 33 and P = {2, 3, 5, 7, 11, 13, 17, 19}
n(P) = 8
⇒ n(S) + n(P) = 33 + 8 = 41