Answer:
6 runners
Step-by-step explanation:
Each runner ran 7.5 km. If there were n runners, then (7.5 km)n = 45 km.
Solve this for n by dividing 7.5 km into 45 km:
n = 6
There were 6 runners.
Answer:

Step-by-step explanation:
The given function is

To find the inverse of this function, we interchange x and y.

we now solve for y.

Take the sine inverse of both sides to obtain;

Hence the inverse of the given function is;

where 
Answer:
a) y = 5x
b) y = 60
Step-by-step explanation:
Since, y is directly proportional to x when y=30, x=6

<h2><u>Corect option</u> :</h2>

<h2><u>Answer with steps</u> :</h2>
Quantity of water she needs 
Number of servings she needs = 10
Number of cups of water she will need :



Thus, she needs
of water.
Therefore, the correct option is 
40 percent of 250 = .4*250 = 100
100 seventh graders got the flu.