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Carl can wash all the windows of his house in 6 hours. His wife Maggie

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Bunuel
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Carl can wash all the windows of his house in 6 hours. His wife Maggie [#permalink] New post   16 Nov 2015, 03:25
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A
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C
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Question Stats:

88% (00:58) correct 12% (01:19) wrong based on 147 sessions
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Carl can wash all the windows of his house in 6 hours. His wife Maggie can wash all the windows in 4 hours. How many hours will it take for both of them working together to wash all the windows?

A. 2
B. 2 1/4
C. 2 2/5
D. 4 1/2
E. 5
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C
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Re: Carl can wash all the windows of his house in 6 hours. His wife Maggie [#permalink] New post   16 Nov 2015, 03:30
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In 1 hour, Carl can wash 1/6 of the total windows and Maggie can wash 1/4 of the total windows.

So, in 1 hour, they can wash 1/6 + 1/4 = 5/12 of the windows together.

5/12 in 1 hour
1 in X hours

X = 1/(5/12) = 12/5 = 2 2/5

Hence, (C)
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Re: Carl can wash all the windows of his house in 6 hours. His wife Maggie [#permalink] New post   16 Nov 2015, 03:34
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1/6 + 1/4 = 5/12

Time taken = 12/5 = 2 2/5.

Answer: C
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Re: Carl can wash all the windows of his house in 6 hours. His wife Maggie [#permalink] New post   17 Nov 2015, 01:16
Work hrs=AB/(A+B)= 24/10 =2 2/5
Answer is C
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Re: Carl can wash all the windows of his house in 6 hours. His wife Maggie [#permalink] New post   17 Nov 2015, 10:28
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Bunuel wrote:
Carl can wash all the windows of his house in 6 hours. His wife Maggie can wash all the windows in 4 hours. How many hours will it take for both of them working together to wash all the windows?

A. 2
B. 2 1/4
C. 2 2/5
D. 4 1/2
E. 5


Let there be 24 windows ,

In one hour Carl can wash 4 windows
In one hour Maggie can wash 6 windows

Togathar Maggie & Carl can wash 10 windows in an hour
So, Togathar Maggie & Carl can wash 24 windows 24/10

So, Togathar Maggie & Carl can wash 24 windows 2\(\frac{2}{5}\)

Hence answe is C.
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Re: Carl can wash all the windows of his house in 6 hours. His wife Maggie [#permalink] New post   29 Nov 2015, 12:36
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Hi All,

This question is a standard version of a 'Work Formula' question (it involves 2 'entities' working on the same task together), so we can use the Work Formula to solve it.

Work = (A)(B)/(A+B) where A and B are the individual times that it takes the 2 entities to complete the task on their own.

Here, we're told that Carl can complete the task in 6 hours and that Maggie can complete the task in 4 hours. We're asked how long it would take them, working together, to complete the task...

(6)(4)/(6+4) = 24/10 = 2.4 hours

Final Answer:
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C


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Re: Carl can wash all the windows of his house in 6 hours. His wife Maggie [#permalink] New post   11 Sep 2020, 01:20
Bunuel wrote:
Carl can wash all the windows of his house in 6 hours. His wife Maggie can wash all the windows in 4 hours. How many hours will it take for both of them working together to wash all the windows?

A. 2
B. 2 1/4
C. 2 2/5
D. 4 1/2
E. 5


\(\frac{12}{(2+3)} = 2 \frac{2}{5}\) , Answer must be (C)

PS : Skipped a couple of steps , anyone facing diff plz revert, will be happy to respond...
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Re: Carl can wash all the windows of his house in 6 hours. His wife Maggie [#permalink]
11 Sep 2020, 01:20
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