Kezia9 wrote:

afactor4 wrote:

Convert weeks to days on rates:

New computer: \(\frac{1}{4}\) -> \(\frac{1}{28}\)

Old computer: \(\frac{1}{24}\) -> \(\frac{1}{168}\)

Combine Rates:

\(\frac{1}{28}\)+ \(\frac{1}{168}\)

= \(\frac{1}{24}\)

We need the set of computers to do the job in 6 days, so: if one set takes \(\frac{1}{24}\), we need to add this rate to itself enough times to get \(\frac{1}{6}\)

4 x \(\frac{1}{24}\) gives us \(\frac{1}{6}\)

Therefore answer is 4 (D)

Hi,

I have a doubt. Total days taken to complete the job by the two computers is 24. When I solve it as

1set of computers = 24 days

x=6 days

I get x=1/4. Where am I wrong????

When I solve using per day work I get 4 sets.

1 set = 1/24 days

x = 1/6

x= 4 sets

Can you please clarify???

The

more working sets of computers, the

shorter the time to complete the job.

1 set of computers = 24 days

x sets of computers = 6 days

--> the time to complete the job

decreases 4 times, so the number of sets of computers need to

increases 4 times. In other words, x = 4.

Hope it's clear.

_________________

（＾人＾）

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