If 4 be added to a number and the sum is multiplied by 3, the result is 27. Find the number.

Solution:

Let the number be x. According to the given statement,

3 (x + 4) = 27

=> 3 x + 12 = 27

=> 3 x = 27 - 12 = 15

=> x = 15 / 3 = 5