PareshGmat wrote:

speedilly wrote:

I cannot see this being a GMAT problem - how is one supposed to calculate 1- [1/(.92*1.2)] without a calculator? Even with using fractions I get 13/138 which is also not easily solved.

Agree.. this calculation goes tough. Any simpler way to avoid that 92 & 12 factor?

Hello

My approach is

Name:

S = number of students

P = Price

Q = Quantity of food consumption.

C = total cost

==>

C = S*P*Q

One way to solve this kind of question is

plug in numbers.Assume: before we have 100 students, P = $10 ==> C = 100*10*Q = 1000*Q

After: we have 92 students, P = $12 ==> C' = 92*12*Q' = 1104*Q'

==> 1104*Q' = 1000*Q

==> Q' = 1000/1104*Q = (1 - 104/1104)*Q

==> Q' = Q -

104/1104*QThe red part is the decrease of food consumption. We can guess

104/1104 ~ 9.4% (The ONLY option < 10%) --> E is answer.

Hope it helps.

_________________

Please +1 KUDO if my post helps. Thank you.

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