Posted by **George** on Sunday, February 25, 2007 at 12:40pm.

The average of X numbers is 15. If the sum of the X numbers is 90, what is the value of X? A)5, B)6, C)8, D)15 or E)75

What is the correct answer and how do you set up the equation?

The answer is b)6 because if there are 15 average numbers and the sum is 90 you just multiply 6 x 15 = 90

Thank you!

Beautiful has the right answer but you would divide 90 by 15, not multiply 6 x 15. always work with the numbers you start with. however multiplying 6 by 15 is a good way to check you work. do you understand why you would divide 15 into 90?

Your welcome ;)

If he is given the answer than he can start the way I gave him , if was not given the multiple choices then he could do it your way. But it really doesn't matter ;)

true. :)