Question

Sum of digit of a two digit number is 8. If 180is added to the number the digit change there places. Find the number.

Answer 1

Let unit digit is Y & Tens digit is X

X+Y =8.......1

Number

10×X +Y

ATQ
10X+Y +18= 10×Y +X

9X-9Y =-2

X-Y=-2..........2

subtracting eq 2 from 1
X+Y=8
X-Y = -2


2X= 6

X=3
&

Y= 5

So the number is (10×3 +5) =35
$35$