BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

The number of passengers on a certain bus....

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 162
Joined: Mon Jul 28, 2008 8:33 pm
Location: San Jose,CA
Thanked: 1 times

The number of passengers on a certain bus....

by ddm » Mon Aug 25, 2008 3:27 pm
The number of passengers on a certain bus at any given time is given by the equation
P = -2(S – 4)^2 + 32, where P is the number of passengers and S is the number of stops the bus has made since beginning its route. If the bus begins its route with no passengers, how many passengers will be on the bus two stops after the stop where it has its greatest number of passengers?


32
30
24
14
0

OA-C
Top
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 35
Joined: Thu Aug 21, 2008 2:55 pm
Thanked: 1 times

by kuroneko1313 » Mon Aug 25, 2008 3:58 pm
First we have to find the equation in which there are maximum numbers of passengers in the bus during certain numbers of stop.

P' = -2(2)(s-2)
= -4s + 16

Maximum number of passenger happens when P' = 0

0 = -4s + 16
s = 4

So maximum passenger is reached during the 4th stop.

The question's asking for two stops after the stop where it has its greatest number of passengers, i.e. during the 6th stop. So plug-in the number:

P = -2(6-2)^2 + 32
= -2(4) + 32
= 24

I hope that helps.
Top
Post new topic Post Reply
• Page 1 of 1