Randy can run pi meters every 2 seconds. If the circular track has a r

Question

Randy can run  \pi  meters every 2 seconds. If the circular track has a radius of 75 meters, how many seconds does it take Randy to run twice around the track?

A. 150 seconds
B. 300 seconds
C. 600 seconds
D. 1200 seconds
E. 22500 seconds

Kudos for a correct  solution .

NickHalden · Answer

Length of track = 2πr = 2*75*π = 150π m -------- (1)

Speed = π m in 2 secs = π/2 m per sec ------------ (2)

Total distance = 2 * Length of track = 300π ---------- (3)

Time = dist/speed = 300π/(π/2) = 600.
  Hence C !!

GMATinsight · Answer

Rate =  \pi  meters every 2 seconds =  \pi / 2  meters every seconds. 
Perimeter of Circular Track =  \pi *Diameter =  2*75*\pi  =  150* \pi

Total Distance to be run =  2*150* \pi  =  300* \pi

Time =  300* \pi  /  \pi / 2  second = 600 seconds = 600/60 Mins = 10 Mins

Answer: Option C

But the options should have been in minutes as per the language of the question

adityadon · Answer

speed = pi/2 m/sec

Circumference = 2 pi r = 2*pi*75=150 pi

required length = 2 *150*pi

time = 2*150*pi / Pi/2 
= 600 seconds

Answer C

ENGRTOMBA2018 · Answer

Bunuel , the question asks about minutes while the options are in seconds. Please correct one of them.

\pi  m in 2 seconds are run by Randy. Distance to be covered to run twice around the track :  2*2*\pi*r , as circumference of a circle = 2*\pi*r

Given, r=75 m,

Thus total distance to be covered =  300\pi

Speed =  \pi/2 ms^{-1}

Thus, time = distance/speed =  300\pi / \pi/2 ms^{-1}  = 600 seconds = 10 minutes , C is the correct answer

kanigmat011 · Answer

Option C is correct
speed = pi/2 m/sec

Circumference = 2 pi r = 2*pi*75=150 pi

required length = 2 *150*pi

time = 2*150*pi / Pi/2 
= 600 seconds

Bunuel · Answer

The distance around the track is the circumference of the circle:

C = 2\pi r = 150\pi

Running twice around the circle would equal a distance of  300\pi  meters. If Randy can run  \pi  meters every 2 seconds, he runs  30\pi  meters every minute. Therefore, it will take him 10 minutes to run around the circular track twice.

Answer: C.

stne · Answer

Dear Moderator, 
Came across this good question while going through the forum, there may have been a small oversight here. Question asks how many minutes does does it take Randy ....? But option are given in seconds , is this ok? Thank you.

Bunuel · Answer

________________
Edited. Thank you.

tatz · Answer

Sorry..it's C.. 600

Sent from my SM-G610F using  GMAT Club Forum mobile app

Abhishek009 · Answer

The Circumference of the circle =  2*π*75

Distance covered by Randy is 2* 2*π*75  =  4*π*75

The speed of Randy is  \frac{π}{2}

Time taken to cover the distance is  \frac{4*π*75*2}{π}  = 600 Seconds, Answer must be (C)

ScottTargetTestPrep · Answer

The circumference of the circular track is 2 x π x 75 = 150π, and Randy’s rate is π/2 meters per second. So it will take Randy 2 x 150π / (π/2) = 300π x 2/π = 600 seconds to run around the track twice.

Answer: C

Sabby · Answer

We know that the track radius is 75
Now, we want to know the circumference of the track : 
C=2*n*r
=2*n*75
=150*n
Because Randy runs twice the track, the distance becomes 2*150*n=300*n

Randy's rate is n every 2 seconds, therefore it is 30*n every minute and 300*n every 10 minutes
Therefore he completes his run in 10 minutes which is 600 seconds (10*60 seconds)

Answer C)

aman007yadav · Answer

The distance around the track is the circumference of the circle:
C = 2pir
= 150pi
Running twice around the circle would equal a distance of 3007T meters. If Randy can run n meters 
every 2 seconds, he runs 307T meters every minute. Therefore, it will take him 10 minutes to run around 
the circular track twice.

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Randy can run pi meters every 2 seconds. If the circular track has a r

Prep Toolkit

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