Correct Answer - Option 2 : 4
Concept used:
A digit can not be more than 9
Calculation:
Let the digit in the 10th place and unit place are a and b respectively.
So, the two-digit number is 10a + b.
According to the question,
10a + b + 45 = 10b + a
⇒ 10b + a = 10a + b + 45
⇒ 9b = 9a + 45
⇒ 9b = 9(a + 5)
⇒ b = a + 5
For a = 1, b = 6
a = 2, b = 7
a = 3, b = 8
a = 4, b = 9
∴ There are 4 such two-digit numbers are possible.
