Aarush asked Soham to take a two digit number and reverse it, then subtract the larger number from the smaller number. Soham did the same. This result will be always divisible by_____.
A
5
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
9
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
4
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is B 9 Let's consider a two digit number ab. Its general form will be 10×a+1×b.
If we reverse it, then the number will become ba. Its general form will be 10×b+1×a.
If we subtract both of the numbers, we get: (10×a+1×b)−(10×b+1×a) =9(a−b)
Observe that the result is a multiple of 9 and hence is exactly divisible by 9.