Question

please do it.............with whole process

Answer 1

Let 2 digit number be XY

If digit of ONE's is 1 more than digit of TEN's

Y = X + 1  -----------------------------------------------------[1]

If Digit reversed the difference with original number is 9

⇒ YX - XY = 9

Convert the digits into ONE's and TENS's

10Y + X - (10X + Y) = 9

10Y + X - 10X - Y = 9

9Y - 9X = 9

9 (Y - X) = 9

Y - X = 9/9 = 1

Y = X + 1 -------------------------------------------------------- [2]

Since both equations are same for any number with above criteria [1] & [2] will bring the difference of 9

Its 2 Digit and One's is higher number

12 - 21 = -9

23 - 32 = -9

34 - 43 = -9

45 - 54 = -9

56 - 65 = -9

67 - 76 = -9

78 - 87 = -9

89 - 98 = -9

-9 indicates that new reversed number is 9 more than original number.