Question

sum of the 2 digit no is 9 . If 63 is subracted from the no, its digits are reversed.find the no

Answer 1

Let us assume, x and y are the two digits of a two digit number

Therfore, the two-digit number = 10x + y and reversed number = 10y + x

Given:
x + y = 9 ----------1

Also given:
10x + y - 63 = 10y + x
9x - 9y = 63
x - y = 7 ------------2

Adding equation 1 and equation 2
2x = 16
x = 8
and therefore, y = 9 - x = 9 - 8 = 1

Therefore, the two digit number = 10x + y = 10*8 + 1 = 81