Question

Mrs. Williams is deciding between two field trips for her class. The Science Center charges $80 plus $5 per student. The Dino Discovery Museum simply charges $7 per student. For how many students will the Science Center charge less than the Dino Discovery Museum charges?

fewer than 40 students
78 or fewer students
78 or more students
more than 40 students

HELP!!

Answer 1

Well, I know it isn't A (I learned the hard way). I did more calculations and if you make a chart with different values for x (e.g. 39, 41, 77, and 79), 41 is the first number for x when the Science center charges less than the Dino Discovery Museum. So, D - more than 40. 

Answer 2

Answer: More than 40 students

Explanation:

Let x be the number of students .

Given : Mrs. Williams is deciding between two field trips for her class. The Science Center charges $80 plus $5 per student.

i.e. Total cost :
`80+5x` (1)

The Dino Discovery Museum simply charges $7 per student.

i.e. Total cost :
`7x` (2)

The inequality that shows Science Center charge less than the Dino Discovery Museum charges will be :-

`80+5x<7x`

Subtract 5x on both sides , we get

`80<2x`

Divide both sides by 2 , we get

`40<x`

Hence, for more than 40 students the Science Center charge will less than the Dino Discovery Museum charges.