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# A computer can perform 30 identical tasks in six hours. At

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A computer can perform 30 identical tasks in six hours. At [#permalink]  27 Sep 2017, 14:20
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A computer can perform 30 identical tasks in six hours. At that rate, what is the minimum number of computers that should be assigned to complete 80 tasks within three hours?

[Reveal] Spoiler: OA
6

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Joined: 20 Apr 2016
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Re: A computer can perform 30 identical tasks in six hours. At [#permalink]  27 Sep 2017, 21:42
1
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Carcass wrote:
A computer can perform 30 identical tasks in six hours. At that rate, what is the minimum number of computers that should be assigned to complete 80 tasks within three hours?

[Reveal] Spoiler: OA
6

We Know

Total work = rate * Time

therefore

30 = Rate * 6

or Rate = \frac{30}{6} = 5

Now we need to find the number of computers

total work given = 80 and total time = 3 hrs

therefore

80 = 5 * 3 * No. of computers

or No. of computers = \frac{80}{15} = 5\frac{1}{3}, but no. of computers cannot be fraction i.e \frac{1}{3}, so we have to consider as 1.

Total no. of computers = 5+1 = 6.
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Re: A computer can perform 30 identical tasks in six hours. At [#permalink]  12 Oct 2017, 15:26
1
KUDOS
Expert's post
Carcass wrote:

A computer can perform 30 identical tasks in six hours. At that rate, what is the minimum number of computers that should be assigned to complete 80 tasks within three hours?

[Reveal] Spoiler: OA
6

We can also just apply some logic...

Given: 1 computer can perform 30 tasks in 6 hours
This means 1 computer can perform 15 tasks in 3 hours (half the time means half the output)
So, 2 computers can perform 30 tasks in 3 hours (Double the number of computers means double the output)
And 3 computers can perform 45 tasks in 3 hours
.
.
.
5 computers can perform 75 tasks in 3 hours
6 computers can perform 90 tasks in 3 hours

Since we can't have a FRACTION as our answer, we need 6 computers to complete the 80 tasks within three hours

[Reveal] Spoiler:
6

Cheers,
Brent
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Brent Hanneson – Founder of greenlighttestprep.com

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Joined: 12 Oct 2017
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Re: A computer can perform 30 identical tasks in six hours. At [#permalink]  13 Oct 2017, 03:41
1
KUDOS
Task performed by one computer in 3 hrs = 15

to perform 80 tasks computers required are 80/15 = 5.33

as the computers cannot be in fraction so answer should be 6
Re: A computer can perform 30 identical tasks in six hours. At   [#permalink] 13 Oct 2017, 03:41
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