If the digit in the unit and the ten's places of a two digit number are interchanged, a new number is formed, which is grater then the original number by 63. Suppose the digit in the unit place of the original number the x. Then all the possible value of x are -

A. 7, 8, 9

B. 2, 7, 9

C. 0, 1, 2

D. 1, 2, 8

Answer: Option A

Solution(By Examveda Team)

$$\eqalign{ & {\text{Let the two digit number be }} \cr & 10y + x\,\,\,\,\,{\text{where}}\,\,\,y > x \cr & 10x + y - 10y - x = 63 \cr & 9x - 9y = 63 \cr & x - y = 7 \cr & {\bf{x = 7,8,9}}{\text{ and}} \cr & y = 0,1,2 \cr} $$