Question

A girl has a score of 59 and wants to know how to get a mean of 69. She would like to use two more scores to get that mean. What numbers did she use?

Please help!

Answer 1

Set the problem like this:

59 + x + x / 3 (because it's total 3 tests))

Set the above equal to 69 (your desired result)

SO: 2x + 59 = 207 (which is 69 * 3)

2x = 207 - 59
2x = 148
x = 74

She used to scores of 74 to get a mean of 69. Hope this helps!

Answer 2

FYI You can check the final answer like so:

59 + 74 + 74/3

You should get an answer of 69! Voila!

Answer 3

This is assuming that the two scores are the same. Is that true?

Even if it is, the equation is more clearly written:

(59 + x + x)/3 = 69

Otherwise, it might be assumed that only the last x is divided by 3.

I hope this helps a little more.