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GRE Prep Club Team Member
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Annika hikes at a constant rate of 12 minutes per kilometer. She has
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16 Apr 2021, 02:52
16 Apr 2021, 02:52
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Question Stats:
68% (02:21) correct
31% (02:22) wrong based on 19 sessions
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Annika hikes at a constant rate of 12 minutes per kilometer. She has hiked 2.75 kilometers east from the start of a hiking trail when she realizes that she has to be back at the start of the trail in 45 minutes. If Annika continues east, then turns around and retraces her path to reach the start of the trail in exactly 45 minutes, for how many kilometers total did she hike east?
A) 2.25
B) 2.75
C) 3.25
D) 3.75
E) 4.25
A) 2.25
B) 2.75
C) 3.25
D) 3.75
E) 4.25
Re: Annika hikes at a constant rate of 12 minutes per kilometer. She has
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16 Apr 2021, 03:11
16 Apr 2021, 03:11
1
The following calculation is after she hiked 2.75 km:
if she hikes to the east and returned in 45 minutes exactly, it means at the rate of 12 min per km, she covers 3.75 km in which the hiked(let say x km) and returned(x+2.75)km
so, 3.75=2x+2.5
and , x=0.5
Therefore she hiked 2.75+0.5=3.25km
if she hikes to the east and returned in 45 minutes exactly, it means at the rate of 12 min per km, she covers 3.75 km in which the hiked(let say x km) and returned(x+2.75)km
so, 3.75=2x+2.5
and , x=0.5
Therefore she hiked 2.75+0.5=3.25km
Annika hikes at a constant rate of 12 minutes per kilometer. She has
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18 Apr 2021, 03:15
18 Apr 2021, 03:15
4
Intuitively, if she has traveled from point S ( start ) to the point E (east ), at the rate of 12 km per minute, then, according to the
formula W = RT, we get 12 = R(1) which in turn gives us R = 1/12.
So, for travelling 2.75 km, she would've taken T = 12*2.75 = 33 minutes.
If she has to return in 45 mins, the time she takes to return the distance she has so far traveled is 33.Thus she has 45-33 = 12 minutes left. she still has to move East and then return back. therefore on dividing this 12/2= 6.
So, she goes east for six minutes and comes back again for six minutes and then takes the 33 minutes to travel back the 2.75 km.
Therefore, to calculate the total distance she traveled to east, just add 2.75 + ( distance traveled in 6 minutes)
Distance traveled in 6 minutes = 6/12 = 0.5.
Thus the answer is, 2.75+0.5 = 3.25 which is C.
formula W = RT, we get 12 = R(1) which in turn gives us R = 1/12.
So, for travelling 2.75 km, she would've taken T = 12*2.75 = 33 minutes.
If she has to return in 45 mins, the time she takes to return the distance she has so far traveled is 33.Thus she has 45-33 = 12 minutes left. she still has to move East and then return back. therefore on dividing this 12/2= 6.
So, she goes east for six minutes and comes back again for six minutes and then takes the 33 minutes to travel back the 2.75 km.
Therefore, to calculate the total distance she traveled to east, just add 2.75 + ( distance traveled in 6 minutes)
Distance traveled in 6 minutes = 6/12 = 0.5.
Thus the answer is, 2.75+0.5 = 3.25 which is C.
