Question

Determine whether $12345678$ is divisible by $2,4$or $8$

Answer 1

Divisibility by $2$ : A number is divisible by $2$ if its last ( unit’s) digit is divisible by $2$ I.e., if its last digit is $0,2,4,6$ or $8$

The last digit of $12345678$ is $8$ , which is divisible by $2$ [ $2\times 4=8$] . So, the given number is divisible by $2$

Divisibility by $4$ : A number is divisible by $4$ if the number formed by its last ( unit’s and ten’s ) digits is divisible by $4$.

The number formed by last two digits are $78$ which is not divisible by $4$ . So , the given number is not divisible by $4$.

Divisibility by $8$ : A number is divisible by $8$ if the number formed by its last three ( unit’s , ten’s and hundred’s ) digits is divisible by $8$.

The number formed by last three digits are $678$ which is not divisible by $8$. So, the given number is not divisible by $8$

Hence , $12345678$ is divisible by 2 but not divisible by $4$ and $8$