Question

Mr Shah calculated the average of 10 three digit numbers but due to mistake he reversed the digits of one of the number and thus his average increased by 19.8. The difference between the unit digit and hundreds digit of that number is???​

Answer 1

Given :

The average og 10 numbers = 19.8

To find :

The difference between units digit and hundreds digit of original number

Solution :

• As the average increased by 19.8 and there are 10 numbers the number should be 198 greater than original number
• Let the number be abc and by reversing it becomes cba

      100c+10b+a - (100a+10b+c) = 198

      99c - 99a = 198

      99(c-a) = 198

      c-a = 2

The difference between units digit and hundreds digit of original number is 2