Question

If 31x5 is a multiple of 3,where x is a digit, what might be the value of x​

Answer 1

Answer:

x can be 0, 3, 6, and 9.

Step-by-step explanation:

Thank you.

Answer 2

Answer:

$x$ can be 0, 3, 6, or 9.

Reason:

The number is a multiple of 3, so the remainder should be some multiples of 3.

We have the divisibility test of 3.

This leads to the fact that the digits are added it should give any multiples of 3.

But the known digits add to $9$, which is already a multiple of 3.

This gives the result.

Learn more:

First, let's see the divisibility test of 9. If we show $100$ as $99+1$ and $10$ as $9+1$, and so on, the remainder of each digit is that digit.

Now we add all digits and divide by 9.

Same for the divisibility test of 3. The sum of the digits is already a remainder, so we divide by 3.