Question

The sum of the two digits of a number is 12 if the number is reversed the number is greater than the original number by 18. find the number

Answer 1

ANSWER:-

Let a and b the digit

a+b=12 ........(1)

54+(10a+b)=(10b+a)

54+10a+b=10b+a

9a-9b=-54

a-b=-6........(2)

adding (1) and (2)

a+b=12

a-b=-6

----------

2a=6

a=3

so b=9

39+54=93 (verified)

orig no.=39 and  No. when digits reversed=93