wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

The difference between a 3 digit number and a number formed by reversing its digits is divisible by
  1. 99

Open in App
Solution

The correct option is A 99
Let 100a+10b+c be the original number.
Then, the number obtained by reversing its digits is 100c+10b+a.

Assuming a>c, subtracting smaller number from larger
(100a+10b+c)(100c+10b+a)
=(1001)a+(1010)b+(1100)c
=99a99c=99(ac)
So, it is always divisible by 99.

Now, 99=11×9
Therefore, 99(ac)=11×9(ac)
Hence, the difference obtained is always divisible by 99, 9 and 11.

flag
Suggest Corrections
thumbs-up
18
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Divisibility for 3 and 9
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon