Question

a two digit no. is 3more than 4times the sum of its digit.if 18is add to the no.the digits are reverse.find the no.

Answer 1

Two digit number = 10x + y

According to the question

10x + y = 4(x + y) + 3
10x + y = 4x + 4y + 3
6x - 3y = 3
2x - y = 1. -(1)

10x + y + 18 = 10y + x
9x - 9y = -18
x - y = -2. -(2)

Solving both equation simultaneously

2x - y = 1
x - y = -2
(-) (+) (+)
-----------------
x = 3

Putting the value of x on 1st equation

2x - y = 1
(2*3) - y = 1
y = 5

Two digit number = 10x + y
= (10*3) + 5
=35