Question

The tens digit of a two digit number is thrice that of unit digit .the sum of all the number and unit digit is32 find the number

Answer 1

$x=3y\\10x+y+y=32\\\\x=3y\\10x+2y=32\\\\x=3y\\5x+y=16\\\\5\cdot 3y+y=16\\16y=16\\y=1\\\\x=3\cdot 1=3$

$10\cdot 3+1=31$

It's 31.