Question

The sum of a number times 3 and 15

Answer 1

3n + 3 = 15
3n = 18
n = 6
And...
18 + 3 = 15

Answer 2

`3x+15`

Explanation:

The given statement can be expressed as

`3x+15`

When it says "the sum of a number three times", it refers to
`3x`, because "times" means product.

Then, the problem specifies that the sum is between
`3x` and the number 15.

Therefore, the expressions is
`3x+15`