The 200 seventh graders at John Witherspoon Middle School raised 80%

Question

The 200 seventh graders at John Witherspoon Middle School raised 80% of the funds needed for a field trip. The school donated the remaining 20%. When they went to purchase the tickets, however, they were given a 10% bulk rate discount after a $20 processing fee. Faced with an unexpected surplus the students chose to buy each member of the class one cookie and were still left with $18, which they gave to the bus driver. If each of the cookies cost $0.30, how much did the trip cost the school?

Let the total trip cost be $x.

Discount offered = (x-20)*10% = .3*200 + 18 = 78
x = 800

Trip cost to the school = 800*20% = $160

IMO D

A. $40
B. $80
C. $120
D. $160
E. $200

AvidDreamer09 · Answer

Let the Cost of the tickets be = T

The total amount spent on tickets is =>T-(T-20)*10% = T - (T/10 - 2) = T - T/10 + 2 = 9T/10 + 2

They used the surplus to buy cookies and pay the driver = 0.3*200+$18 = $78

9T/10+2+78=9T+800=10T => Total cost of the trip= 800

The School Paid 20% of the trip cost = 800*20% = 160

Hence D

sahilkak · Answer

can you please elaborate on equation

9T/10+2+78=9T+800=10T => Total cost of the trip= 800

AvidDreamer09 · Answer

sahilkak  ill try explaining it another way.

Total Cost of the trip is say= T
but then they got an unexpected discount of 10% on T and that is = 10% of (T-20) and they used that to buy cookies and pay the driver so 200(total students) * 0.03(cost per cookie)+18 (Drivers fee) = $78

so 10%*(T-20)=78
10/100*(T-20)=78
T-20=780
T=800

ScottTargetTestPrep · Answer

We can let n = the total cost of trip. They were charged: a processing fee of $20, 90% of the remaining n - 20, 200 cookies at $0.3 each. They also paid $18 to the driver; therefore:

n= 20 + 0.9(n - 20) + 0.3(200) + 18

n = 20 + 0.9n - 18 + 60 + 18

0.1n= 80

n = 800

Since the school paid 20% of the total cost of the trip, the school paid 0.2 x 800 = $160.

Answer:D

stne · Answer

Hi  ScottTargetTestPrep ,
Thank you for your solution, but you have actually arrived at c and NOT option D. Can you please check your solution? Thanks.

ScottTargetTestPrep · Answer

Nice catch. Just adjusted my solution.

Fdambro294 · Answer

Tricky, wordy question.

If they were given a discount of 10% AFTER a $20 processing fee, then this is the surplus that was spent on the 200 cookies.

Let T = Total Price of the trip

10% (T - $20) ———-> spent on $0.30 priced cookies for 200 students + an additional $18

10%(T - 20) = (200)(.3) + 18

.1(T) - 2 = 60 + 18

.1(T) = 80

1(T) = 800

T = $800 is the total price of the field trip

The school donated ONLY 20% of this amount.

10% of 800 ——-> 80

So 20% ————> 160

Answer: $160

Posted from my mobile device

Purnank · Answer

T as a total expense amount of discount 10% is actually lead to buying cookies + $ 18 to driver 
(T-20)*1/10 = 200*0.3 + 18
T/10 - 2 = 60 + 18
T / 10 = 80
T=800
expense to school was 20% 0.2T = 160
Answer D.

kop18 · Answer

Hi  Bunuel   KarishmaB   ScottTargetTestPrep

Shouldn't the processing fees get added to the total cost? Its a fee so ideally it should increase the expense.
In the light of this question, I have assumed the cost for the trip to be x, then the total cost after the discount should be
= 0.9 $(x+20).
I am doing this because $x was required to purchase tickets for the 200 students on which a $20 processing fees has been charged, making my total cost $x+$20. On this cost when the discount is offered then my surplus becomes = 10%(x+20), reducing my cost to 0.9 $(x+20).

Does this make sense?
Please could u advise where I am going wrong.

Kinshook · Answer

The 200 seventh graders at John Witherspoon Middle School raised 80% of the funds needed for a field trip. The school donated the remaining 20%. When they went to purchase the tickets, however, they were given a 10% bulk rate discount after a $20 processing fee. Faced with an unexpected surplus the students chose to buy each member of the class one cookie and were still left with $18, which they gave to the bus driver. If each of the cookies cost $0.30, how much did the trip cost the school?

Let the total trip cost be $x.

Discount offered = (x-20)*10% = .3*200 + 18 = 78
x = 800

Trip cost to the school = 800*20% = $160

IMO D

Let the total trip cost be $x.

Discount offered = (x-20)*10% = .3*200 + 18 = 78
x = 800

Trip cost to the school = 800*20% = $160

IMO D

KarishmaB · Answer

Processing fee is a flat fee for every transaction. Hence  I read the question stem again to confirm but this is what it says -  they were given a 10% bulk rate discount after a $20 processing fee.
The "after" makes me think that (200*Ticket Cost + 20) was the amount on which discount was given. I am not sure what I would do here. Likely calculate this way first, not get an answer, and then calculate the way they meant us to.

kop18 · Answer

Hopefully this kind of amiguity will not be present in an actual GMAT question

Regor60 · Answer

Not a well-worded question

Posted from my mobile device

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The 200 seventh graders at John Witherspoon Middle School raised 80%

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