Question

Which of the following numbers are divisible by $12$?

• A. $816$
• B. $699$
• C. $1222$
• D. $1728$

Answer 1

Answer: (A), (D)

$1728$

For a number to be divisible by $12$, it has to be divisible by $3$ and $4$ both.

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

Divisibility by 4: A number, whose last two digits are divisible by 4, is also divisible by 4.

Option (a) sum of digits of the number $816$ is $15$ which is a multiple of $3$ and last two digits of the number are divisible by $4$. So, the number $816$ is divisible by $12$.

Option (b) sum of digits of the number $699$ is $24$ which is a multiple of $3$ and last two digits of the number are also not divisible by $4$. So, the number $699$ is not divisible by $12$.

Option (c) sum of digits of the number $1222$ is $7$ which is not a multiple of $3$ and last two digits of the number are also not divisible by $4$. So, the number $1222$ is not divisible by $12$.

Option (d) sum of digits of the number $1728$ is $18$ which is a multiple of $3$ and last two digits of the number are also divisible by $4$. So, the number $1728$ is divisible by $12$.