Question

digit at tens place of two digit number is twice the digit at units place .if sum of this number and the no.formed by reversing the digit is 66,. find the number

Answer 1

Let the number be     xy ,

xy = 10x + y.   when reversed = yx = 10y + x

x = 2y          ........(a)

10x + y + 10y + x = 66.........(b)

10(2y) + y + 10y + 2y = 66

20y + y + 10y + 2y = 66

33y = 66

y = 66/33

y = 2

x = 2y = 2*2 = 4

Recall the original number is xy =     42.