Question

A number consist of two digits whose sum is 8 if 18 added to the no. Its digit are reversed. Find the no.

Answer 1

Answer:

Let the digit at ones place be x.

Therefore, number at tens place = 8-x.

Number, 10(8-x) + 1(x)

= 80 - 10x + x

= 80 - 9x

When interchanged:

Digit at ones place= 8-x

Digit at tens place= x

Number = 10(x) + 1(8-x)

= 10x+ 8 - x

= 9x+8

ATQ

80-9x+18=9x+8

98-9x=9x+8

98-8=9x+9x

90=18x

90/18=x=5

Therefore, number= 80-9x

= 80-45

=35

Hope it helped :D