Question

23. The digits of a two-digit number differ by 3. If the digits are interchanged, and the resulting number is added to the original number, we get 143. What can be the original number?

Answer 1

Let the unit digit be x

Tens digit => x+3x+3

10(x+3)+x10(x+3)+x

digits interchanged =10x+x+3=10x+x+3

10(x+3)+x+10x+x+3=14310(x+3)+x+10x+x+3=143

=> 10x+30+12x+3=14310x+30+12x+3=143

=> 22x+33=14322x+33=143

22x=143−3322x=143−33

22x=11022x=110

x=11022x=11022

x=5x=5

Original number = 85