Question

The table below shows function r, which represents the total cost of a field trip to the science museum, in dollars, if n students return permission slips to attend. Which function represents the situation?

A.
r(n) = 15n + 55
B.
r(n) = 55n + 15
C.
r(n) = 30n - 20
D.
r(n) = 5n + 45

Answer 1

The answer has to be A) r(n) = 15n +55, as when n=0, r(n)=55 so the equation must end with +55.

Answer 2

A.
`r(n)=15*n+55`

Explanation

Since the value of n is given in the table as 0,5,15,30 and 35.So we will put the value of n in the given option starting from A.

Now putting the value of n as 0 in option A

we get
`r(n)=15*n+55`

`r(0)=15*0+55\\r(0)=55`

Now putting the value of n as 5 in option A

we get
`r(n)=15*n+55`

`r(5)=15*5+55\\r(0)=130`

Now putting the value of n as 15 in option A

we get
`r(n)=15*n+55`

`r(15)=15*15+55\\r(0)=280`

Now putting the value of n as 30 in option A

we get
`r(n)=15*n+55`

`r(30)=15*30+55\\r(0)=505`

Now putting the value of n as 35 in option A

we get
`r(n)=15*n+55`

`r(35)=15*35+55\\r(0)=580`

After seeing the results of each value we see that option A is matching with all the given values. So the correct answer is A.