Hello. I recently encountered this question on a math test, and it totally stumped me.
The mean of a set of numbers is 0.40. The sum of the numbers is 56. How many numbers are in the set?
I guessed 14 (completely random guess). The correct answer turned out to be 140. It was a multiple choice question, but I forgot what the other two choices were.
I know that when somebody tells me how to figure it out, it'll seem really dumb and obvious, but I just can't see how to right now. It's the only question on the test that I had no idea how to solve. Any help that anyone could give me would be greatly appreciated!