Practice | Hashtable

Home > Practice > Arithmetic Aptitude > Problem on Numbers > Miscellaneous

1. The difference between a two-digit number and the number obtained by interchanging the positions of its digits is 36. What is the difference between the two digits of the number ?

A. 3

B. 4

C. 9

D. Cannot be determined

Solution:

Let the ten's digit be x and unit's digit be y
Then,

\begin{aligned} \Leftrightarrow (10 x + y) - (10 y + x) = 36 \\ \Leftrightarrow 9 (x - y) = 36 \\ \Leftrightarrow x - y = 4 \end{aligned}

You must login to add comments. Login now.