take 2 monkeys

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take 2 monkeys

by sanju09 » Thu May 13, 2010 4:18 am
Suppose 7 monkeys take 7 minutes to eat 7 bananas. How many minutes would it take 2 monkeys to eat 2 bananas?
(A) 2
(B) 2.5
(C) 3
(D) 3.5
(E) 7
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by selango » Thu May 13, 2010 4:26 am
7 minutes

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by selango » Thu May 13, 2010 4:34 am
For this type of work prob we can use the formula,

(M1*D1*H1)/W1=(M2*D2*H2)/W2

M-->Number of persons

D-->Number of days

H--> Number of hours

W-->Work done


So (7*7)/7=(2*x)/2

Hence 7

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by sanju09 » Thu May 13, 2010 4:35 am
selango wrote:For this type of work prob we can use the formula,

(M1*D1*H1)/W1=(M2*D2*H2)/W2

M-->Number of persons

D-->Number of days

H--> Number of hours

W-->Work done


So (7*7)/7=(2*x)/2

Hence 7
good
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by dtweah » Thu May 13, 2010 6:14 am
sanju09 wrote:Suppose 7 monkeys take 7 minutes to eat 7 bananas. How many minutes would it take 2 monkeys to eat 2 bananas?
(A) 2
(B) 2.5
(C) 3
(D) 3.5
(E) 7
The best way to handle these problems which can be tricky is to use intuition. Formulas will lose u when the problem isTWEAKED. Always reduce it to amount of job done in a unit of time. 7 monkeys doing 7 mins gives 49 monkey - mins. Forget about the 7 bananas yet. This could be filling a drum, typing a paper etc. It is important for determining the fraction of the work done. You ALWAYS want to know how much time it takes 1 monkey to do the job in a unit of time. This important animal is 1/49 MON-MIN. So from here u can see that this important fraction can be multipled by a number with units MOn-MIN. The problem asks how many mins it takes 2 monkeys. So we get 2 monkeys times X mins which gives 2X mon-min.

2X mon-min./ 49 mon-min is some fraction of the job done.

2bananas/7bananas should be the same fraction of the job

Since these two fractions MUST be the SAME ( one is in units of mon-min while the other is in units of bananas and the units cancel). You are just looking for the X that MAKES them equal.

2X/49= 2/7

X=7 mins, since u were solving for time.
Last edited by dtweah on Thu May 13, 2010 6:17 am, edited 1 time in total.

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by sanju09 » Thu May 13, 2010 6:17 am
dtweah wrote:
sanju09 wrote:Suppose 7 monkeys take 7 minutes to eat 7 bananas. How many minutes would it take 2 monkeys to eat 2 bananas?
(A) 2
(B) 2.5
(C) 3
(D) 3.5
(E) 7
The best way to handle these problems which can be tricky is to use intuitive. Formulas will lose u when the problem isTWEAKED. Always reduce it to amount of job done in a unit of time. 7 monkeys doing 7 mins gives 49 monkey - mins. Forget about the 7 bananas yet. This could be filling a drum, typing a paper etc. It is important for determining the fraction of the work done. You ALWAYS want to know how much time it takes 1 monkey to do the job in a unit of time. This important animal is 1/49 MON-MIN. So from here u can see that this important fraction can be multipled by a number with units MOn-MIN. The problem asks how many mins it takes 2 monkeys. So we get 2 monkeys times X mins which gives 2X mon-min.

2X mon-min./ 49 mon-min is some fraction of the job done.

2bananas/7bananas should be the same fraction of the job

Since these two fractions MUST be the SAME ( one is in units of mon-min while the other is in units of bananas and the units cancel). You are just looking for the X that MAKES them equal.

2X/49= 2/7

X=7 mins, since u were solving for time.
very helpful and informative
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by harshavardhanc » Thu May 13, 2010 6:48 am
Regards,
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by quantskillsgmat » Sat May 15, 2010 3:23 am
7x7/7=2xt/2 so t =7
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