Seven times a two digit number is equal to four times the number obtained by reversing the order of its digits. If the difference of the digits is 3, determine the number.

### Answer

Let the ten’s and the unit's digit be y and x respectively.

So, the number is 10y + x.

The number when digits are reversed is 10x + y.

Now, 7(10y + x) = 4(10x + y)

2y = x … (i)

Also, x – y = 3 … (ii)

Solving (i) and (ii), we get

y = 3 and x = 6

Hence, the number is 36.