Question

?/1 If a test is worth 45 points, how many points would a student need to earn to get a score of 90%?

Answer 1

Answer:

40.5 points

Step-by-step explanation:

To start off, I would set up a proportion. You're trying to find how many points out of the total 45 would give you a 90%.

90% as a fraction would be $\frac{90}{100}$.

When you set the two equal to one another, you get this:

$\frac{x}{45} = \frac{90}{100}$

The bottom numbers are the total amount of points, and the top is how many points a student got.

To solve for x, which is the number of points a student would need to earn, you can cross multiply.

After you do that, you should get:

100x = 4050

To isolate x, you can divide by 100 on both sides.

x = $\frac{4050}{100}$ = 40.5 points

To check your answer, all you have to do is divide.

40.5 ÷ 45 = 0.9

0.9 as a percent is 90%.