It is currently 22 Sep 2017, 21:02

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Average speed

Author Message
Manager
Joined: 05 May 2005
Posts: 77

Kudos [?]: 57 [0], given: 0

### Show Tags

17 Aug 2007, 17:18
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

How would you solve?

A bicyclist travels uphill from town A to town B for 2 hours at an average speed of 4 miles per hour and returns along the same road at an average speed of 6 miles per hour. What is the bicyclist’s average speed for the round trip, in miles per hour?

a) 4 4/5
b) 5
c) 5 1/5
d) 5 2/5
e) 5 3/5

Kudos [?]: 57 [0], given: 0

VP
Joined: 10 Jun 2007
Posts: 1436

Kudos [?]: 330 [0], given: 0

### Show Tags

17 Aug 2007, 17:25
above720 wrote:
How would you solve?

A bicyclist travels uphill from town A to town B for 2 hours at an average speed of 4 miles per hour and returns along the same road at an average speed of 6 miles per hour. What is the bicyclist’s average speed for the round trip, in miles per hour?

a) 4 4/5
b) 5
c) 5 1/5
d) 5 2/5
e) 5 3/5

A.

Uphill: 2 hour @ 4mph
Total distance = 4*2 = 8 miles
Down hill time: 1/6 * 8 = 4/3
Average Speed = Total Distance / Total Time = 16 / (2+4/3)
Avg Speed = 16 / (10/3) = 4 4/5.

Kudos [?]: 330 [0], given: 0

Director
Joined: 03 May 2007
Posts: 871

Kudos [?]: 248 [0], given: 7

Schools: University of Chicago, Wharton School

### Show Tags

17 Aug 2007, 17:28
above720 wrote:
A bicyclist travels uphill from town A to town B for 2 hours at an average speed of 4 miles per hour and returns along the same road at an average speed of 6 miles per hour. What is the bicyclist’s average speed for the round trip, in miles per hour?

a) 4 4/5
b) 5
c) 5 1/5
d) 5 2/5
e) 5 3/5

= (2x4 + 8) / (2 + 8/6)
= 16/ (20/6)
= 16x6/20
= 4 4/5

A.

Kudos [?]: 248 [0], given: 7

VP
Joined: 09 Jul 2007
Posts: 1098

Kudos [?]: 139 [0], given: 0

Location: London

### Show Tags

17 Aug 2007, 18:14
above720 wrote:
How would you solve?

A bicyclist travels uphill from town A to town B for 2 hours at an average speed of 4 miles per hour and returns along the same road at an average speed of 6 miles per hour. What is the bicyclist’s average speed for the round trip, in miles per hour?

a) 4 4/5
b) 5
c) 5 1/5
d) 5 2/5
e) 5 3/5

This kind of problems(rate problems are explained in details in MGMAT Word Translations)
U should not just find the average of two given speed rates, the average speed is found by dividing the total distance by the total time to travel the distance.
First find the distance traveled by byciclist to town B S=t*v (t-time, v-speed) S = 2*4=8
now find the time spent for coming from b to a, t=S/v or t=8/6
So now Total time he spent in his trip to and from A is 2+(4/3) or 10/3
Total distance of trip is 2*8 or 16
so the average speed he travelled is 16/(10/3) or 4 4/5, A

Kudos [?]: 139 [0], given: 0

Director
Joined: 12 Jul 2007
Posts: 857

Kudos [?]: 327 [0], given: 0

### Show Tags

17 Aug 2007, 19:40
definitely A.

2 hours * 4mph = 8 miles each way
8 miles @ 6mph = 4/3 hour
so total trip was 16 miles in 10/3 hour (2 there, 4/3 back)
(16*3)/10 = 4.8

or 4 4/5 mph

A

Kudos [?]: 327 [0], given: 0

17 Aug 2007, 19:40
Display posts from previous: Sort by