Last year at a certain high school, there were $100$ ninth graders on the honor roll and $150$ tenth graders on the honor roll. This year, the number of ninth graders on the honor roll increased by $17\%$ and the number of tenth graders on the honor roll increased by $24\%$ . By what percentage did the total number of students on the honor roll increase? Round your answer to the nearest tenth (if necessary). $\newline$ Answer: ◻

Full solution

Q. Last year at a certain high school, there were

100

ninth graders on the honor roll and

150

tenth graders on the honor roll. This year, the number of ninth graders on the honor roll increased by

17\%

and the number of tenth graders on the honor roll increased by

24\%

. By what percentage did the total number of students on the honor roll increase? Round your answer to the nearest tenth (if necessary).

\newline

Answer: ◻

Ninth Graders Honor Roll Increase: Last year's ninth graders on honor roll: $100$ Increase by $17\%$ this year: $100 \times 0.17 = 17$ New number of ninth graders on honor roll: $100 + 17 = 117$
Tenth Graders Honor Roll Increase: Last year's tenth graders on honor roll: $150$ Increase by $24\%$ this year: $150 \times 0.24 = 36$ New number of tenth graders on honor roll: $150 + 36 = 186$
Total Students Honor Roll Last Year: Total number of students on honor roll last year: $100 + 150 = 250$ $\newline$ Total number of students on honor roll this year: $117 + 186 = 303$
Total Students Honor Roll This Year: Increase in total number of students on honor roll: $303 - 250 = 53$ Percentage increase: \frac{$53$}{$250$} \times \(100 = $21$ . $2$ \%$