The science club at Jersey High School is sponsoring a dance to raise money for their spring project. They will charge $4 per student admission, but must pay $140 for publicity and chaperones. If n is the number of students who attend the dance, how many students must attend if the science club is to earn at least $640?

Answer: 195

Step-by-step explanation:

Cost per student = $4

Total number who attended = n

The cost of the total of student who attended will be cost per student multiplied by the total number of students, that is

Total cos = 4n

Since, they are to pay $140, for publicity, then the total cost becomes

T = 4n - 140

From the last statement

4n - 140 ≥ 640

4n ≥ 640 + 140

4n ≥780

n ≥ 780/4

n ≥ 195

That means at least 195 students must attend if the science club is to earn at least $ 640