S6-6 What is the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters in a straight line without slipping?
(1) The diameter of the bicycle wheel, including the tire, was 0.5 meter.
(2) The wheel made twenty 360-degree rotations per minute.
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Number of 360-degree rotations that a bicycle wheel made
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mehravikas
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The number of rotations = total distance/distance traveled in 1 rotationmehravikas wrote:S6-6 What is the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters in a straight line without slipping?
(1) The diameter of the bicycle wheel, including the tire, was 0.5 meter.
(2) The wheel made twenty 360-degree rotations per minute.
We know the total distance, so we need to know the distance traveled in one rotation. For a circle, that's merely the circumference.
(1) Gives us diameter, so we can calculate circumference: sufficient.
(2) Gives us rate, which has nothing to do with the size of the circle: insufficient.
(1) is suff, (2) isn't: choose (A).
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GMAT680
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Doesn't statement 2 mean it needs 20 revolution to complete the 100 meters. Hence, 2*PI*r*20 = 100 and solve for r.
I thought this is enough information to solve the problem.
My answer is D and I am still not convinced. Can someone tell me why I am wrong?
I thought this is enough information to solve the problem.
My answer is D and I am still not convinced. Can someone tell me why I am wrong?
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kstv
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What is the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters in a straight line without slipping?
(1) The diameter of the bicycle wheel, including the tire, was 0.5 meter.
(2) The wheel made twenty 360-degree rotations per minute.
You are assuming that it covered 100 mts in 20 revolutions.
Doesn't statement 2 mean it needs 20 revolution to complete the 100 meters. Hence, 2*PI*r*20 = 100 and solve for r.
Why even bother to calculate the part - 2*PI*r*20 = 100 and find r - you have to find the no of revolutions . Qs is
What is the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters. According to you it is 20.
(1) The diameter of the bicycle wheel, including the tire, was 0.5 meter.
(2) The wheel made twenty 360-degree rotations per minute.
You are assuming that it covered 100 mts in 20 revolutions.
Doesn't statement 2 mean it needs 20 revolution to complete the 100 meters. Hence, 2*PI*r*20 = 100 and solve for r.
Why even bother to calculate the part - 2*PI*r*20 = 100 and find r - you have to find the no of revolutions . Qs is
What is the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters. According to you it is 20.
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Solution:mehravikas wrote: ↑Tue Jun 03, 2008 1:48 pmS6-6 What is the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters in a straight line without slipping?
(1) The diameter of the bicycle wheel, including the tire, was 0.5 meter.
(2) The wheel made twenty 360-degree rotations per minute.
We need to determine the number of 360-degree rotations that a bicycle wheel made while rolling 100 meters in a straight line without slipping. If we can determine the circumference of the wheel, then we can determine the number of 360-degree rotations. For example, if the circumference of the wheel is 5 meters, then the number of the 360-degree rotations is 100/5 = 20.
Statement One Alone:
Since we know the diameter of the wheel, we can determine the circumference of the wheel and hence the number of 360-degree rotations. Statement one alone is sufficient.
Statement Two Alone:
Knowing the wheel made twenty 360-degree rotations per minute does not allow us to determine the circumference of the wheel. Hence, we can’t determine the number of 360-degree rotations. Statement two alone is not sufficient.
Answer: A
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