Question

Choose the number(s) that is/ are divisible by both $3$ and $8.$

• A. $1016$
• B. $1031$
• C. $1080$
• D. $1104$

Answer 1

Answer: (C), (D)

$1104$

Divisibility by 3: A number, whose sum of digits is divisible by 3, is also divisible by 3.

Divisibility by 8: A number, whose last three digits are divisible by 8, is also divisible by 8.

For divisibility by both the numbers, we need to check the conditions individually.

For $1016,$ sum of the digits is $1+0+1+6=8,$ which is not divisible by $3.$

For $1031,$ sum of the digits is $5,$ which is not divisible by $3.$

For $1080,$ sum of the digits is $9,$ which is divisible by $3.$
Also, the last there digits are $080,$ which is divisible by $8.$

Similarly, $1104$ is divisible by both $3$ and $8.$