Question

Do
Make 3 different 3 digit numbers using 1,9 and 8, where each digit can be used only once.
Check which of these numbers are divisible by 9.​

Answer 1

Answer:

198, 891, 918 - all divisible by 9

Explanation -

There is a trick which helps you see the divisibility of 9, which is - if the sum of the digits is divisible by 9, the number is divisible by 9.

So, all of these digits have the same sum, which is 18, and 18/9=2

therefore, we can see that all of these numbers are divisible by 9. Check it on a calculator if you aren't sure :)

Answer 2

Answer:

198

891

918

All the numbers will be divisible by 9.

Divisibility rule of 9 :-

Add all the digits, and the sum should be divisible by 9.

In all the cases, the sum is the same i.e. 18.

Hence, all are divisible by 9.