Racquet manufacurer

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Racquet manufacurer

by sl750 » Fri Sep 09, 2011 4:36 am
At a certain factory that operates 24 hours per day, of the daily output of

tennis racquets are flawed. If only these racquets are rejected, how many

racquets must be produced per hour to yield 1,320 acceptable racquets

per day?


55
60
75
110
120

I don't know whether I misinterpreted the question incorrectly or whether the question needs to be reworded.

"how many racquets must be produced per hour to yield 1,320 acceptable racquets per day?"
Doesn't this ask for the number of accepted racquets?,i.e after excluding the flawed ones out?
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by GMATGuruNY » Fri Sep 09, 2011 5:05 am
At a certain factory that operates 24 hours per day, 1/12 of the daily output of tennis racquets are flawed. If only these racquets are rejected, how many racquets must be produced per hour to yield 1,320 acceptable racquets per day?

A.55
B.60
D.75
E.110
E.130
I've added crucial information that was missing: the fraction of the racquets that are flawed.
We can plug in the answers, which represent the number of racquets that must be produced each hour.
Since 1/12 are flawed, the correct answer is likely to be a multiple of 12.

Answer choice B: 60 total racquets each hour.
Number rejected each hour = (1/12)*60 = 5.
Number of acceptable racquets each hour = 60-5 = 55.
In 24 hours, number of acceptable racquets produced = 24*55 = 1320.
Success!

The correct answer is B.
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by knight247 » Fri Sep 09, 2011 9:52 am
Let the number of racquets produced in day be x
Number of flawed racquets=x/12
Number of acceptable racquets=x-x/12= 11x/12

Now, if 1320 acceptable racquets have to produced in a day then 11x/12=1320 so x=1320*12/11=120*12=1440

So 1440 racquets have to be produced in a day which includes both the flawed and acceptable racquets.
In 24 hrs 1440 racquets need to be produced so in 1 hr the number of racquets to be produced=1440/24=720/12=60 Hence B