At a certain instant in time, the number of cars, \(N,\) traveling on a portion of a certain highway can be estimated by

This topic has expert replies
Legendary Member
Posts: 2898
Joined: Thu Sep 07, 2017 2:49 pm
Thanked: 6 times
Followed by:5 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

At a certain instant in time, the number of cars, \(N,\) traveling on a portion of a certain highway can be estimated by the formula

\(N=\dfrac{20Ld}{600+s^2}\)

where \(L\) is the number of lanes in the same direction, \(d\) is the length of the portion of the highway, in feet, and s is the average speed of the cars, in miles per hour. Based on the formula, what is the estimated number of cars traveling on a \(\frac12\)-mile portion of the highway if the highway has \(2\) lanes in the same direction and the average speed of the cars is \(40\) miles per hour? (5,280 feet = 1 mile)

(A) 155
(B) 96
(C) 80
(D) 48
(E) 24

Answer: D

Source: Official Guide

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 7223
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members
Vincen wrote:
Mon May 03, 2021 10:40 am
At a certain instant in time, the number of cars, \(N,\) traveling on a portion of a certain highway can be estimated by the formula

\(N=\dfrac{20Ld}{600+s^2}\)

where \(L\) is the number of lanes in the same direction, \(d\) is the length of the portion of the highway, in feet, and s is the average speed of the cars, in miles per hour. Based on the formula, what is the estimated number of cars traveling on a \(\frac12\)-mile portion of the highway if the highway has \(2\) lanes in the same direction and the average speed of the cars is \(40\) miles per hour? (5,280 feet = 1 mile)

(A) 155
(B) 96
(C) 80
(D) 48
(E) 24

Answer: D

Source: Official Guide
Solution:

Substituting 2 for L, 40 for s and 2640 for d (since ½ mile = 2640 feet), we have:

N = (20 x 2 x 2640) / (600 + 40^2)

N = 105,600/2200 = 48

Answer: D

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage