Question

Last year at a certain high school, there were 130 boys on the honor roll and 140 girls on the honor roll. This year, the number of boys on the honor roll increased by 10% and the number of girls on the honor roll increased by 15%. By what percentage did the total number of students on the honor roll increase? Round your answer to the nearest tenth (if necessary)

Answer 1

We have to find 10% of 130 boys

$0.10\cdot130=13$

There are 13 boys more.

Let's find 15% of 140 girls

$0.15\cdot140=21$

There are 21 more.

The total would be

$130+13+140+21=304$

Before the increases, the total was

$130+140=270$

Now, we divide

$\frac{304}{270}=1.1259$

Let's multiply by 100 to express it in percent

$1.1259\times100=112.6$

Hence, the increase of the total was 12.6% (because that's the difference from 100%).