Rate and Distance

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Rate and Distance

by BTGmoderatorRO » Sat Sep 30, 2017 7:42 pm
Anne traveled from City A to City B in 4 hours, and her speed was between 25 miles per hour and 45 miles per hour. John traveled from City A to City B along the same route in 2 hours, and his speed was between 45 miles per hour and 60 miles per hour. Which of the following could be the distance, in miles, from City A to City B?
A. 95
B. 115
C. 125
D. 160
E. 180
oa is b.

I am confused on how to set up the formulas here. Can any experts help?

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by GMATGuruNY » Sun Oct 01, 2017 2:35 am
Roland2rule wrote:Anne traveled from City A to City B in 4 hours, and her speed was between 25 miles per hour and 45 miles per hour. John traveled from City A to City B along the same route in 2 hours, and his speed was between 45 miles per hour and 60 miles per hour. Which of the following could be the distance, in miles, from City A to City B?
A. 95
B. 115
C. 125
D. 160
E. 180
Anne:
Traveling for 4 hours at a speed of 25 mph, the distance traveled = rt = 25*4 = 100 miles.
Traveling for 4 hours at a speed of 45 mph, the distance traveled = rt = 45*4 = 180 miles.
Since Anne's speed was between 25 mph and 45 mph, the distance from A to B must be BETWEEN 100 AND 180 MILES.
Eliminate A and E, which are not between 100 and 180.

John:
Traveling for 2 hours at a speed of 45 mph, the distance traveled = rt = 45*2 = 90 miles.
Traveling for 2 hours at a speed of 60 mph, the distance traveled = rt = 60*2 = 120 miles.
Since John's speed was between 45 mph and 60 mph, the distance from A to B must be BETWEEN 90 AND 120 MILES.
Eliminate C and D, which are not between 90 and 120.

The correct answer is B.
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Re: Rate and Distance

by Scott@TargetTestPrep » Wed Jan 29, 2020 5:18 am
BTGmoderatorRO wrote:
Sat Sep 30, 2017 7:42 pm
Anne traveled from City A to City B in 4 hours, and her speed was between 25 miles per hour and 45 miles per hour. John traveled from City A to City B along the same route in 2 hours, and his speed was between 45 miles per hour and 60 miles per hour. Which of the following could be the distance, in miles, from City A to City B?
A. 95
B. 115
C. 125
D. 160
E. 180
oa is b.

I am confused on how to set up the formulas here. Can any experts help?
Let’s use the minimum and maximum speeds.

Minimum for Anne: 25 x 4 = 100 miles

Maximum for Anne: 45 x 4 = 180 miles

Thus:

100 < d < 180

Minimum for John: 45 x 2 = 90 miles

Maximum for John: 60 x 2 = 120 miles

Thus:

90 < d < 120

Using both inequalities, we have:

100 < d < 120

Answer: B

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