IMO E
60 seconds (1 min) = x revolutions
k seconds = (kx)/60 revolutions
wots the OA
GmatPrep?? (Revolutions)
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Source: Beat The GMAT — Problem Solving |
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parallel_chase
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x revolutions per minutedferm wrote:Correct..but how did you arrive to your answer.
x/60 revolutions per seconds
kx/60 revolutions per k seconds
Hence E.
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mals24
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well yeah you can plug in numbers
for instance the wheel completes 10(X) rev in 1 min or 60 secs
how many rev does it complete in 15 (K) secs
60 secs = 10 rev
15 secs = z rev
cross multiply and solve for z = (15*10)/60
which is the same as (kx)/60
btw i just cross multiplied the values to get the answer
for instance the wheel completes 10(X) rev in 1 min or 60 secs
how many rev does it complete in 15 (K) secs
60 secs = 10 rev
15 secs = z rev
cross multiply and solve for z = (15*10)/60
which is the same as (kx)/60
btw i just cross multiplied the values to get the answer
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parallel_chase
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Sure why not!dferm wrote:CAN YOU PLUG IN #'S..
let x be 60
60 revolutions in 1 minute.
60 revolutions in 60 secs.
1 revolution per sec.
let k be 10
10*1= 10
if you plugin values of x and k in the answer choices only E will give 10 as the answer.
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mlane25269
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Here's how I solved...
pick numbers for both x and k. The easiest would be 10 for x and 120 for k since there are 60 seconds in a minute so the question would really be asking you how many revolutions are made in two minutes. In this case it would be 20 so all we need to do is plug in the values for x =10 and k = 120 into each of the answer choices (i would start with C) and see which ones yields a value of 20.
E gives us a value of 20.
Hope this helps!!
pick numbers for both x and k. The easiest would be 10 for x and 120 for k since there are 60 seconds in a minute so the question would really be asking you how many revolutions are made in two minutes. In this case it would be 20 so all we need to do is plug in the values for x =10 and k = 120 into each of the answer choices (i would start with C) and see which ones yields a value of 20.
E gives us a value of 20.
Hope this helps!!
