The average test score of RSM students in September increased by 20%. In October it increased by another 15%. By what percent did the average score on the test increase during the two months?
26.5
38
To find the percent increase in the average test score during the two months, we need to calculate the combined effect of the two separate increases of 20% and 15%.
Let's start by considering a hypothetical scenario where we have a test score of 100 for a single student in September. After the 20% increase, the test score becomes 100 + (20% of 100) = 100 + 20 = 120.
Now, let's apply the 15% increase to this new score of 120. The increase would be 120 + (15% of 120) = 120 + 18 = 138.
So, when we combine the two increases, the score increases from 100 to 138. To find the percent increase, we calculate the difference between the final score and the initial score, divided by the initial score, and then multiply by 100:
Percent increase = ((final score - initial score) / initial score) * 100
= ((138 - 100) / 100) * 100
= 38%
Therefore, the average test score increased by 38% during the two months.
increases expressed as a single increase
= 1.2(1.15)
= 1.38
it increased by 38%