Bunuel wrote:
Tommy's office organizes company trips from its employees. The company allows employees to register for the trip for a down payment of $63, a 10% markup over the amount the company spends per person on this trip. If employees change their minds, they can cancel their registration but will receive only a 90% refund on their payment. If 100 people registered for the trip but 50 canceled, and if the company does not spend money on canceled registrations, then what was Tommy's office's approximate profit or loss on the trip as a percentage of their total expenses?
A. 15% loss
B. 20% loss
C. 10% profit
D. 15% profit
E. 20% profit
Quick thinking: The minimum profit is 10% if all went. The profit % will keep increasing as more cancellations are done. For example if all cancel the profit percentage is infinite as the profit is over ZERO expenditure.
Thus only D and E are left. 10% was the profit on markup price of 63.
But the remaining 50 too are giving 10% of actual cost as profit without any excess expenditure. Thus 10%+10% over the actual expenditure of 50 person.
Answer : 20%
Arithmetic 110% of the actual cost = 63, so actual cost = \(63*\frac{100}{110}\).
Since 50 employees went for the trip, the actual cost = \(\frac{6300}{110}*50=\frac{6300*5}{11}\)
The profit per person is 10% of actual cost, so profit for all 100 person = \(63*\frac{100}{110}*\frac{10}{100}*100=\frac{6300}{11}\)
Profit % = \(\frac{\frac{6300}{11}}{\frac{6300*5}{11}}*100=20\)
E