The ten's digit of a 2­digit number is greater than the units digit by 4. If we subtract 36 from the number, the new number obtained is a number formed by interchange of the digits. Find the number.

Let the unit's digit of the number be $$y$$ and ten's digit be $$x$$

=> Number = $$10x + y$$

According to ques, => $$x - y = 4$$ --------------(i)

According to question, => $$10x + y - 36 = 10y + x$$

=> $$9x - 9y = 36$$

=> $$x - y = \frac{36}{9} = 4$$ --------------(ii)

Equations (i) and (ii) are same and thus we have two variables and one equation

Number can be = 95 , 84 , 73 , 62 , 51 , 40 and thus the solution cannot be determined.

=> Ans - (D)