Question

In a two digit number the one's digit is 3 times the ten's digit. If 10 is added to the 2 times of the number, its digits interchange their places in the new number. Find the number

Answer 1

Let the two numbers be x and y

x = 3y ( given )

( 10x + y ) + ( 10y + x ) = 88 (given )

11x + 11y = 88

x + y = 8

Implies, 3y + y = 8

y = 2 and x = 6