Divisibility Rule of 15: Rule, Examples

Divisibility Rule of 15

A number is divisible by 15 if it is divisible by both 3 and 5 at the same time.

1. Divisible by 3 -> The sum of its digits is a multiple of 3.
2. Divisible by 5 -> The last digit is 0 or 5.

If both rules are true, then the number is divisible by 15.

Steps to Check Divisibility by 15

1. Check if the number is divisible by 3 (add up the digits and see if the sum is a multiple of 3).

2. Check if the number is divisible by 5 (the last digit should be 0 or 5).

3. If both conditions are true, then the number is divisible by 15.

Examples

Example 1: Is 345 divisible by 15?

1. Check divisibility by 3: 3 + 4 + 5 = 12 (12 is a multiple of 3).

2. Check divisibility by 5: 345 ends in 5 (It’s divisible by 5).

345 is divisible by 15.

Example 2: Is 780 divisible by 15?

1. Check divisibility by 3: 7 + 8 + 0 = 15 (15 is a multiple of 3).

2. Check divisibility by 5: 780 ends in 0 (It’s divisible by 5).

780 is divisible by 15.

Example 3: Is 276 divisible by 15?

1. Check divisibility by 3: 2 + 7 + 6 = 15 (15 is a multiple of 3).

2. Check divisibility by 5: 276 ends in 6 (It’s not divisible by 5).

276 is not divisible by 15.

Try It Yourself:

Are they divisible by 15?
1. 1245
2. 3510
3. 4278