Question

Let A = {x : x is a multiple of 3} and B = { x : x is a multiple of 5}. Then A $\cap$ B is given by:

• A. {15, 30, 45,...}
• B. {3, 6, 9,...}
• C. {15, 10, 15, 20...}
• D. {5, 10, 20,...}

Answer 1

Answer: (A)

Given : A = {3, 6, 9, 15....} and B = {5, 10, 15, 20,.....}
A $\cap$ B = {x : x is multiple of 3 and 5}
$\Rightarrow$ A $\cap$ B = {x : x is multiple of 15}
$\Rightarrow$ A $\cap$ B = {15, 30, 45,....}