Question

I need help with this math question I already solved the first question but I don't understand the second.

Answer 1

We can solve this question using cross multiplication,

If the number of students who sleep 6 hours a day increases by, this means we'll have a total of 6 students who sleep 6 hours a day.

We want the ratio to be same: 15%

Then we can write:

`(6)/(N)=(15\%)/(100\%)`

6 students are the 15%, then N students are the 100%

Now solve for N:

`\begin{gathered} 6·100=15·N \\ \end{gathered}`
`N=(600)/(15)`
`N=40`

The answer is 40 students are expected.

This is a reasonable answer, given that if the number of students who sleep 6 hours doubles, for the rate to remain the same, the total of students must double.