#### Answer

The number is 6

#### Work Step by Step

Let X represent the number we need to find:
Three times a certain number means 3X.
If 6 is added to three times a certain number, we write 6 + 3X.
Thus: $6 + 3X = 24$
Subtract 6 from both sides:
$3X = 18$
Divide both sides by 3:
$X = 6$