Question

In a 2 digit number the unit digit is twice the 10's digit. If 27 is added to the number digits interchange their places. Find the number.

Answer 1

Hey

Here is your answer,

Let the digits be x and y

Then the two-digit number is 10x + y

Given that,
y=2x______ eq.1

27+10x+y = 10y+x
10x-x+y-10y=-27
9x-9y=-27
÷9
x-y=-3______eq.2

Substitute y = 2x in equation 2,
x-2x =-3
-x=-3
x=3

y=2x
y=2x3
y=6

Number = 10x+y
=10x3+6
=30+6
=36

Hope it helps you!