Question

The sum of .the digits of after two digit number is 12 if 18 is added to it the digits are reversed find the number.

Answer 1

Answer:

Let the unit digit be b and tens digit be a, number will be 10a + b.

Sum of digits = 12

a + b = 12

a = 12 - b ----(1)

When 18 is added, digits are reversed so the new number is 10b + a.

According to the question-

= > 10a + b + 18 = 10b + a

= > 9a - 9b = - 18

= > a - b = - 2

a = 12 - b

= > 12 - b - b = - 2

= > 14 = 2b

= > 7 = b

Substituting value in (1)

= > a = 12 - b

= > a = 12 - 7

= > a = 5

Hence the number is 57