Question

Let $S=\{x:x$ is a positive multiple of 3 less than 100$\}$ and $P=\{x:x$ is a prime number less than $20\}$. Then, $n(S)+n(P)$ is equal to

• A. 34
• B. 41
• C. 33
• D. 30

Answer 1

Answer: (B)

$S=\{3,6,9,\dots ,99\}$
$n(S)=33$
$P=\{2,3,5,7,11,13,17,19\}$
$n(P)=8$
$n(S)+n(P)=33+8=41$