Question

Replace the *2,189 with the smallest digit to make it divisible by 9

Answer 1

Answer:

7

Note:

• Divisibility rule for 9 :-

If the sum of all the digits of a number is divisible by 9 , then the number itself will be divisibile by 9 (otherwise it will not be divisibile by 9).

Solution:

The given number is *2189

We need to replace * with the smallest digit so that *2189 become divisibile by 9.

Now,

Sum of all the known digits of *2189

= 2+1+8+9

= 20

Now,

Let's think a number which is just greater than 20 and divisibile by 9 .

That number is 27.

Now,

Let's think about should be added to 20 to make it 27 .

The digit is 7 .

Hence,

* should be replaced by 9 so that the given number become divisibile by 9.

Verification:-

The number obtained after replacing * by 7 will be 72189.

Sum of digits = 7 + 2 + 1 + 8 + 9 = 27

Since,

The sum of the digits (ie; 27) is divisible by 9 , thus 72189 is also divisibile by 9 .