If the number obtained on interchanging the digits of a two digit number is 18 more than the original number and the sum of the digits is 8, then what is the original number?	Choose the most appropriate option:
A) 25  B) 30  C) 35  D) 40  E) 45
Sol.   Let ten's digit = x.   Then, unit's digit = (8-x).   ∴ [10 (8-x)+x] - [10x + (8-x)] = 18   ⇔ 18x = 54   ⇔x = 3   So, ten's digit = 3 and units digit = 5.   Hence, original number = 35.   Answer 35
<result>C</result>
If the number obtained on interchanging the digits of a two digit number is 18 more than the original number and the sum of the digits is 8, then what is the original number?