Question

The digits of a two digit number differ by 4. If the Digits are interchanged and the resulting number is added to the original number we get 154. What is the original number? *​

Answer 1

Answer:

Let the two digit number be xy.

The digit of a two digit number differ by 3.

Hence, x - y = 3 ...(i)

The digit are interchanged and the resulting number is added to the original number we get 143.

10x + y + 10y + x = 143

11x + 11y = 143

x + y = 13...(ii)

Solving (i) and (ii) we get x = 8 and y = 5 Hence, the original number is 85.

Answer 2

Answer:

Let the unit digit be xTens digit => x+3x+310(x+3)+x10(x+3)+xdigits interchanged =10x+x+3=10x+x+310(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=14322x=143−3322x=143−3322x=11022x=110x=11022x=11022x=5x=5Original number = 85