Question

At Townsend High School there are four class years 9th grade, 10th grade grade, and 12th grade There are 300 students in the 9th grade year and as the class year increases each subsequent grade year has approximately 20% more students in its class than does the previous year (For example the 10th grade class year has 20% more students in it than the grade class year) About how many students attend Townsend High School in total

Answer 1

We are asked to determine the total number of students in a school. To do that we need to add the number of students in each of the year classes. Beginning with the 9th class we have:

$N_9=300$

Now, the number of students in the 10th year class is 20% more, this means:

$N_{10}=300+300\times\frac{20}{100}=360$

Now, the number of students in the 11th year class is:

$N_{11}=360+360\times\frac{20}{100}=432$

The 12th year class is:

$N_{12}=432+432\times\frac{20}{100}=518.4$

Now we add all the students in each class:

$\begin{gathered} N=N_9+N_{10}+N_{11}+N_{12} \\ N=300+360+432+518.4 \\ N=1610.4 \end{gathered}$

Therefore, there are about 1610 students in Townsend High School.