|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
24 Oct 2016, 09:50
Kudos
Bookmarks
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
35%
(medium)
Question Stats:
79% (02:53) correct
21%
(03:09)
wrong
based on 479
sessions
History
Date
Time
Result
Not Attempted Yet
Bill spends two days driving from Point A to Point B. On the first day, he drove 2 hours longer and at an average speed 5 miles per hour faster than he drove on the second day. If during the two days he drove a total of 680 miles over the course of 18 hours, what was his average speed on the second day, in miles per hour?
A) 20
B) 25
C) 28
D) 30
E) 35
A) 20
B) 25
C) 28
D) 30
E) 35
Updated on: 20 Dec 2019, 08:41
Originally posted by BrentGMATPrepNow on 24 Oct 2016, 10:09.
Last edited by BrentGMATPrepNow on 20 Dec 2019, 08:41, edited 1 time in total.
Last edited by BrentGMATPrepNow on 20 Dec 2019, 08:41, edited 1 time in total.
Kudos
Bookmarks
grantcke
First recognize that we have TWO pieces of information regarding the time Bill spent driving each day.
On day 1, Bill drove 2 hours longer than he drove on day 2.
So, let x = # of driving hours on day 2
Then x + 2 = # of driving hours on day 1
Bill drove a TOTAL of 18 hours
So, x + (x + 2) = 18
Simplify: 2x + 2 = 18
Solve, x = 8
So, Bill drove 10 hours on day 1 and he drove 8 hours on day 2
Now let's solve the question by starting with a word equation.
Let x = speed driven on day 2
So, x + 5 = speed driven on day 1
(Distance traveled on day 1) + (Distance traveled on day 2) = 680
Distance = (rate)(time)
We get: (x+ 5)(10) + (x)(8) = 680
Expand: 10x + 50 + 8x = 680
Simplify: 18x + 50 = 680
18x = 630
x = 35 (mph)
Answer:
Cheers,
Brent
RELATED VIDEO
General Discussion
24 Oct 2016, 10:02
Kudos
Bookmarks
10 (x+5) + 8x = 680
Solve for X = 35
Explanation:
Lets say he drove at X mi/hr on second day and he drove for Y hours
Question says he drove 2 hrs extra on day 1 so day 1 hours = Y + 2
Speed on day 1 is 5 mi/hr faster so, speed on day 1 = x + 5
Total time he drove (Day 1 + Day 2) = 18
Y + (Y+2) = 18
Y = 8 (Second day's time)
Y + 2 = 10 (First day's time)
Total distance covered = 680 = Speed of day 1* time for day + Speed of day2* time of day2
Putting values we get the very first equation.
HTH
Solve for X = 35
Explanation:
Lets say he drove at X mi/hr on second day and he drove for Y hours
Question says he drove 2 hrs extra on day 1 so day 1 hours = Y + 2
Speed on day 1 is 5 mi/hr faster so, speed on day 1 = x + 5
Total time he drove (Day 1 + Day 2) = 18
Y + (Y+2) = 18
Y = 8 (Second day's time)
Y + 2 = 10 (First day's time)
Total distance covered = 680 = Speed of day 1* time for day + Speed of day2* time of day2
Putting values we get the very first equation.
HTH
