If Kyle works alone, he can wash the night shift dishes in 55 minutes.

Question

If Kyle works alone, he can wash the night shift dishes in 55 minutes. It will only take him 40 minutes if he works, together with Harry. How long will it take Harry to wash the night shift dishes by himself?

A. 65
B. 87
C. 95
D. 147
E. 165

A. 65
B. 87
C. 95
D. 147
E. 165

yashikaaggarwal · Answer

If Kyle works alone, he can wash the night shift dishes in 55 minutes. It will only take him 40 minutes if he works, together with Harry. 
So, 
Let Harry complete work in x minutes
And they do 1/55 & 1/x work in 1 minute
1/55 + 1/x = 1/40
(X+55)/55x = 1/40
40X+2200 = 55x
2200 = 15X
X = 146.666
Or X = 147

Answer is D

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VERBAL1 · Answer

Kyle's rate: 55 minutes
Rate of work together: 40 minutes
Harry's rate : h

using the combined rates formula :ab/ a+ b........ 55h/ 55+ h=40 
solving for h, we get h=146.66

OA: D. 147

TestPrepUnlimited · Answer

Notate K and H as their  efficiencies .

Translating the information gives K = 1/55 and K + H = 1/40.

55 = 5*11 and 40 = 5*8, their LCM is 5 * 8 * 11.

H = 1/40 - 1/55 =  \frac{11}{440} - \frac{8}{440}  =  \frac{3}{440} .

However this is his efficiency, the amount of time needed is 1/H = 440/3 which is a little smaller than 150.

Ans: D

If Kyle works alone, he can wash the night shift dishes in 55 minutes.

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If Kyle works alone, he can wash the night shift dishes in 55 minutes.

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