# Math Help - test average

1. ## test average

You have an 85% average in math after 2 tests. If you score a 40% on this test, what will your new average be?

2. Originally Posted by DINOCALC09
You have an 85% average in math after 2 tests. If you score a 40% on this test, what will your new average be?
lets count by points. so 85% means you average 85 points.

Now $\mbox{Average Score } = \frac {\mbox{Sum of scores}}{\mbox{Number of scores}}$

So, your old average was $\frac {170}2$ %

your new average is $\frac {170 + 40}3$ %

3. Originally Posted by DINOCALC09
You have an 85% average in math after 2 tests. If you score a 40% on this test, what will your new average be?
$\frac{x + y}{2} = 85 \Rightarrow x + y = 170$.

$\frac{x + y + 40}{3} = ? \Rightarrow \frac{170 + 40}{3} = ? \Rightarrow ? = ......$.

If the third test was on finding averages, you should get 60% as the answer .......