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If x persons take y days to complete z similar jobs, how long does it

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If x persons take y days to complete z similar jobs, how long does it  [#permalink]

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New post 06 Mar 2016, 07:45
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Question Stats:

58% (01:25) correct 42% (01:44) wrong based on 130 sessions

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If x persons take y days to complete z similar jobs, how long does it take y persons to complete 1 such job?

A. z
B. x
C. x/y
D. z/x
E. x/z
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Re: If x persons take y days to complete z similar jobs, how long does it  [#permalink]

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New post 06 Mar 2016, 07:58
1
vinoo7 wrote:
If x persons take y days to complete z similar jobs, how long does it take y persons to complete 1 such job?

A. z
B. x
C. x/y
D. z/x
E. x/z

Sorry guys..dont know the Ans


hi,
the Q doesn't seem to be having the any correct answer as a choice..

since we are looking for days, lets keep days in end and work out a solution..
x person can do z jobs in y days..
so x person can do 1 job in y/z days..
and 1 person can do 1 job in y^2/z days..
so y person can complete 1 job in y^2/zy=y/z..
so the answer should be y/z
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Re: If x persons take y days to complete z similar jobs, how long does it  [#permalink]

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New post 09 Nov 2016, 08:06
chetan2u wrote:
vinoo7 wrote:
If x persons take y days to complete z similar jobs, how long does it take y persons to complete 1 such job?

A. z
B. x
C. x/y
D. z/x
E. x/z

Sorry guys..dont know the Ans


hi,
the Q doesn't seem to be having the any correct answer as a choice..

since we are looking for days, lets keep days in end and work out a solution..
x person can do z jobs in y days..
so x person can do 1 job in y/z days..
and 1 person can do 1 job in y^2/z days..
so y person can complete 1 job in y^2/zy=y/z..
so the answer should be y/z


I didn’t understand the logic in the red coloured line.. Could you please help in understanding the same?


Alternatively,
I solved as follows..

X people * Y days ----> produce Z jobs ----- (1)
Now,
Y people * X days -----> must produce Z jobs ----- (2)

>>>> Hence, to produce 1 job, divide above equation (2) by Z.
Y people *(X/Z) days -----> 1 job

The answer should be X/Z.
I think original answer choice E posted in the question before editing was correct.. If I am wrong can anyone please point out what is wrong in my thinking?
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Re: If x persons take y days to complete z similar jobs, how long does it  [#permalink]

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New post 09 Nov 2016, 10:38
MorningRunner wrote:
chetan2u wrote:
vinoo7 wrote:
If x persons take y days to complete z similar jobs, how long does it take y persons to complete 1 such job?

A. z
B. x
C. x/y
D. z/x
E. x/z

Sorry guys..dont know the Ans


hi,
the Q doesn't seem to be having the any correct answer as a choice..

since we are looking for days, lets keep days in end and work out a solution..
x person can do z jobs in y days..
so x person can do 1 job in y/z days..
and 1 person can do 1 job in y^2/z days..
so y person can complete 1 job in y^2/zy=y/z..
so the answer should be y/z


I didn’t understand the logic in the red coloured line.. Could you please help in understanding the same?


Alternatively,
I solved as follows..

X people * Y days ----> produce Z jobs ----- (1)
Now,
Y people * X days -----> must produce Z jobs ----- (2)

>>>> Hence, to produce 1 job, divide above equation (2) by Z.
Y people *(X/Z) days -----> 1 job

The answer should be X/Z.
I think original answer choice E posted in the question before editing was correct.. If I am wrong can anyone please point out what is wrong in my thinking?


Got the same thing (X/Z). I don't understand how chetan2u got what he got in the portion you highlighted. Either he missed something or we're clearly missing something. Experts,help?
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Re: If x persons take y days to complete z similar jobs, how long does it  [#permalink]

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New post 10 Nov 2016, 07:30
peekaysan wrote:
Got the same thing (X/Z). I don't understand how chetan2u got what he got in the portion you highlighted. Either he missed something or we're clearly missing something. Experts,help?


Yes, the correct answer is x/z. Edited the options.
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Re: If x persons take y days to complete z similar jobs, how long does it  [#permalink]

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New post 11 Nov 2016, 02:36
x person - z jobs in y days
x person - 1 job in y/z days
1 person - 1 job in y/zx days
y person - 1 job in y^2/zx
Am I missing something ?? Is'nt the right way to do it ??
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Re: If x persons take y days to complete z similar jobs, how long does it  [#permalink]

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New post 11 Nov 2016, 08:30
1
chetan2u wrote:
vinoo7 wrote:
If x persons take y days to complete z similar jobs, how long does it take y persons to complete 1 such job?

A. z
B. x
C. x/y
D. z/x
E. x/z



We are given that x people take y days to complete z similar jobs. Since rate = work/time, we can determine the rate of x people:

rate of x people = z/y

To determine the rate for y people to complete 1 job, we can use a proportion to determine the rate of y people, in which n = the rate of y people. Our proportion read as:

“x people is to a rate of z/y as y people is to a rate of n”

x/(z/y) =y/n

xn = y(z/y)

xn = z

n = z/x

Since we have the rate of y people, we now can determine the time it takes for y people to complete 1 job.

time = work/rate

time = 1/(z/x) = x/z

Answer: E
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Re: If x persons take y days to complete z similar jobs, how long does it  [#permalink]

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Re: If x persons take y days to complete z similar jobs, how long does it &nbs [#permalink] 03 Aug 2018, 22:51
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