Question

Match the numbers on the left column with their respective divisibility on the right column

• A. Only 3, 5, 9 and 15
• B. Only 2
• C. $2,3,4,5,6,8,9,10,12,15$
• D. Only 3 and 9

Answer 1

1234
The unit's digit is even, so it is divisible by 2.

6561 = 6 + 5 + 6 + 1 = 18
The sum of the digits of the number is 18 which is divisible by 3 and 9.

2565 = 2 + 5 + 6 + 5 = 18
The sum of the digits of the number is 18 which is divisible by 3 and 9.
The unit's digit is 5, so the number is divisible by 5 as well.
If the number is divisible by 3 and 5, it should be divisible by 15.

5400 - 5 + 4 + 0 + 0 = 9
The sum of the digits of the number is 9 which is divisible by 3 and 9.
The unit's digit is 0, so the number should be divisible by 2, 5, 10
The last two digits is 00, so the number is divisible by 4 and 8.
The number is divisible by 2 and 3, so it is also divisible by 6.
The number is divisible by 3 and 4, so it is also divisible by 12.
The number is divisible by 3 and 5, so it is also divisible by 15.