Which expression below is a counterexample to the following statement?
if a number is divisible by 3, then it is divisible by 6.
a. 42 is divisible by 3, so it is divisible by 6.
b. 15 is divisible by 3, but is not divisible by 6.
c. 18 is divisible by 6, so it is divisible by 3.
d. 6 is divisible by 2 and 3, so it is divisible by 6.

B.15 is divisible by 3, but is not divisible by 6.

Step-by-step explanation:

We are given that a statement

If a number is divisible by 3 , then it is divisible by 6.

We have to find that which expression is a counterexample to the given statement.

If a number is divisible by 3 then it is not necessary the number is divisible by 6.

Therefore, given statement is false.

Example:a number is 15.

It is divisible by 3 but, it is not divisible by 6.

Hence, option B is true.

B.15 is divisible by 3, but is not divisible by 6.