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A can complete a piece of work in x days and B can do the same piece o

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Kritisood
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A can complete a piece of work in x days and B can do the same piece o [#permalink] New post   05 Jun 2020, 07:28
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A can complete a piece of work in x days and B can do the same piece of work in y days. If B starts working a day after A and then they work together, in how many days can they complete the work?

1. x = 100
2. x: y = 2: 1
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C
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chetan2u
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Re: A can complete a piece of work in x days and B can do the same piece o [#permalink] New post   05 Jun 2020, 21:11
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Kritisood wrote:
A can complete a piece of work in x days and B can do the same piece of work in y days. If B starts working a day after A and then they work together, in how many days can they complete the work?

1. x = 100
2. x: y = 2: 1


We require to know the rate of work of both to determine the answer.

1. x = 100
We do not know the rate of work of other.
Insuff

2. x: y = 2: 1
We know the relative ratio but not exact values.
Say y=1 and x=2 days. so A will finish half the work in 1 day, and on second day, both will work to finish the work.
But if y=100 and x=200, the days will be much higher.
Insuff

Combined.
we know x=100, so y=50.
We can find the answer now.

C
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Re: A can complete a piece of work in x days and B can do the same piece o [#permalink] New post   05 Jun 2020, 21:48
chetan2u wrote:
Kritisood wrote:
A can complete a piece of work in x days and B can do the same piece of work in y days. If B starts working a day after A and then they work together, in how many days can they complete the work?

1. x = 100
2. x: y = 2: 1


We require to know the rate of work of both to determine the answer.

1. x = 100
We do not know the rate of work of other.
Insuff

2. x: y = 2: 1
We know the relative ratio but not exact values.
Say y=1 and x=2 days. so A will finish half the work in 1 day, and on second day, both will work to finish the work.
But if y=100 and x=200, the days will be much higher.
Insuff

Combined.
we know x=100, so y=50.
We can find the answer now.

C

Sir, have you taken x:y as working ratio or days ratio?

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chetan2u
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Re: A can complete a piece of work in x days and B can do the same piece o [#permalink] New post   05 Jun 2020, 22:10
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yashikaaggarwal wrote:
chetan2u wrote:
Kritisood wrote:
A can complete a piece of work in x days and B can do the same piece of work in y days. If B starts working a day after A and then they work together, in how many days can they complete the work?

1. x = 100
2. x: y = 2: 1


We require to know the rate of work of both to determine the answer.

1. x = 100
We do not know the rate of work of other.
Insuff

2. x: y = 2: 1
We know the relative ratio but not exact values.
Say y=1 and x=2 days. so A will finish half the work in 1 day, and on second day, both will work to finish the work.
But if y=100 and x=200, the days will be much higher.
Insuff

Combined.
we know x=100, so y=50.
We can find the answer now.

C

Sir, have you taken x:y as working ratio or days ratio?

Posted from my mobile device


It is number of days taken to complete the work.
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lacktutor
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A can complete a piece of work in x days and B can do the same piece o [#permalink] New post   05 Jun 2020, 22:34
A —\(\frac{1}{x}\)
B— \(\frac{1}{y }\)

—> \(\frac{1}{x}+ \frac{1}{y} =\frac{( 1–\frac{1}{x})}{a}\)
a—???

(Statement1): x= 100
No info about what y is
Insufficient

(Statement2): x :y = 2 :1
x= 2y
—> still cannot find the solution due to x and y
Insufficient

Taken together 1&2,
x= 100
y = 50
—> \(\frac{1}{100} + \frac{1}{50} = \frac{(1–\frac{1}{100})}{a} \)

\(\frac{3}{100} = \frac{(\frac{99}{100})}{a}\)

\(a = 33\)
Sufficient

Answer (C)

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Re: A can complete a piece of work in x days and B can do the same piece o [#permalink] New post   14 Oct 2020, 04:50
(1) Not able to determine the value of y. Insufficient.

(2) We're not able to determine the days from a given ratio. Insufficient.

(1&2) We know x = 100 days and y = 50 days. We can determine the number of days they take to complete the job. Sufficient.
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Re: A can complete a piece of work in x days and B can do the same piece o [#permalink] New post   14 Dec 2021, 19:26
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Re: A can complete a piece of work in x days and B can do the same piece o [#permalink]
14 Dec 2021, 19:26
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