When fifteen is reduced by one-third of a number, the result is 12. find the number

The number is 9.

Solution:

Let the number be x.

In the question it is given that when 15 is reduced from one-third of a number the result is 12. Since we have assumed the number to be x, therefore one - third of a number is given by  1/3x.

Using the below equation we will try to find the value of x.

Grouping the terms,

Therefore,

x=9

Thus, the number is 9.