Al and Ben are drivers for SD Trucking Company. One snowy day, Ben left SD at 8:00 a.m. heading east and Al left SD at 11:00 a.m. heading west. At a particular time later that day, the dispatcher retrieved data from SD's vehicle tracking system. The data showed that, up to that time, Al had averaged 40 miles per hour and Ben had averaged 20 miles per hour. It also showed that Al and Ben had driven a combined total of 240 miles. At what time did the dispatcher retrieve data from the vehicle tracking system?
A. 1:00 p.m.
B. 2:00 p.m.
C. 3:00 p.m.
D. 5:00 p.m.
E. 6:00 p.m.
OA B
Source: Official Guide
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Al and Ben are drivers for SD Trucking Company. One snowy da
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BTGmoderatorDC
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Brent@GMATPrepNow
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Let's start with a "word equation"BTGmoderatorDC wrote:Al and Ben are drivers for SD Trucking Company. One snowy day, Ben left SD at 8:00 a.m. heading east and Al left SD at 11:00 a.m. heading west. At a particular time later that day, the dispatcher retrieved data from SD's vehicle tracking system. The data showed that, up to that time, Al had averaged 40 miles per hour and Ben had averaged 20 miles per hour. It also showed that Al and Ben had driven a combined total of 240 miles. At what time did the dispatcher retrieve data from the vehicle tracking system?
A. 1:00 p.m.
B. 2:00 p.m.
C. 3:00 p.m.
D. 5:00 p.m.
E. 6:00 p.m.
OA B
Source: Official Guide
(Ben's travel distance) + (Al's travel distance) = 240 miles
Let t = Al's travel time (in hours)
So, t + 3= Ben's travel time (since Ben spent 3 more hours driving)
Distance = (rate)(time)
So, our word equation becomes...
(20)(t + 3) = (40)(t)
Expand: 20t + 60 = 40t
Subtract 20t from both sides: 60 = 20t
Solve: t = 3
So, AL traveled for 3 hours (which means BEN traveled for 6 hours)
So, the dispatcher retrieved data at 2pm (since 8am + 6 hours = 2pm)
Answer: B
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Let's say Ben drove "y" hours and Al drove "x" hours.
We know that the sum of both they're hours took them to drive 240 miles
\(40x+20y= 240\)
And we know that Al left 3 hours after Ben
\(y=x+3\)
So we just replace y in the first equation
\(40x+20(x+3)=240\)
\(40x+20x+60=240\)
\(60x=180\)
\(x=3\)
Since AL left at 11, then 11+3 means the dispatcher retrieved the data at 2:00 pm or 14:00.
We know that the sum of both they're hours took them to drive 240 miles
\(40x+20y= 240\)
And we know that Al left 3 hours after Ben
\(y=x+3\)
So we just replace y in the first equation
\(40x+20(x+3)=240\)
\(40x+20x+60=240\)
\(60x=180\)
\(x=3\)
Since AL left at 11, then 11+3 means the dispatcher retrieved the data at 2:00 pm or 14:00.
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Scott@TargetTestPrep
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Let t represent the time passed between the departure of Al (11:00 a.m.) and the retrieval of data by the dispatcher. Since Ben left at 8 a.m., his time is (t + 3). Since they both traveled for a total 240 miles, we can use the formula distance = rate x time and create the following equation:BTGmoderatorDC wrote:Al and Ben are drivers for SD Trucking Company. One snowy day, Ben left SD at 8:00 a.m. heading east and Al left SD at 11:00 a.m. heading west. At a particular time later that day, the dispatcher retrieved data from SD's vehicle tracking system. The data showed that, up to that time, Al had averaged 40 miles per hour and Ben had averaged 20 miles per hour. It also showed that Al and Ben had driven a combined total of 240 miles. At what time did the dispatcher retrieve data from the vehicle tracking system?
A. 1:00 p.m.
B. 2:00 p.m.
C. 3:00 p.m.
D. 5:00 p.m.
E. 6:00 p.m.
OA B
Source: Official Guide
Ben's distance + Al's distance = 240
20(t + 3) + 40t = 240
20t + 60 + 40t = 240
60t = 180
t = 3 hours
Thus, it was 11 a.m. + 3 hours = 2 p.m. when the dispatcher retrieved data from the vehicle tracking system.
Answer: B
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