If Dale works at full efficiency he needs a break of 1 day after every

Hi All,

There's a visual 'component' to this question that will probably help you to solve it.

We're told that there are 2 ways for Dale to complete a job:

1) Full Efficiency: 2 days of work followed by 1 day "off" for a total of 11 days.
2) Reduced Efficiency: 11 straight days with no days off.

Working at Full Efficiency creates the following pattern:

2 days on, 1 day OFF, 2 days on, 1 day OFF, 2 days on, 1 day OFF, 2 days on = 2+1+2+1+2+1+2 = 11 days
Totals: 8 days on, 3 days off

Reduced Efficiency means that Dale will do 8 days of work in 11 days, thus those Reduced "days" are 8/11 of Full Efficiency.

Final Answer:

GMAT assassins aren't born, they're made,
Rich

One more for D
At full efficiency Dale works for 2+2+2+2 = 8 days, and 3 days rest.
At reduced efficiency Dale works for full 11 days.
Thus fraction = 8/11

VERITAS PREP OFFICIAL SOLUTION:

If Dale needs to rest every third day at full efficiency, that means he'll rest on days 3, 6, and 9 before finishing the job on day 11. That means that he'll have worked a total of 8 days, accomplishing 1/8 of the job each day.

At reduced efficiency, he works a total of 11 days, completing 1/11 of the job each day.

Therefore, the ratio of his output at reduced to his output at full is 1/11 : 1/8. That reduces to 8/11.

When Dale works at full efficiency, he actually works 8 days of the 11 days (notice that 2 + 1 + 2 + 1 + 2 + 1 + 2 = 11). When Dale works at reduced efficiency, he works 11 days.

If we let his output at reduced efficiency = r and his output at full efficiency = f, then we have:

11r = 8f

r/f = 8/11

Answer: D

I learned efficiency a bit differently, so this method was easier.

Full efficiency, X = one day's work:
X X _ X X _ X X _ X X = \(\frac{1Job}{8days}\)

Reduced efficiency:

X X X X X X X X X X X = \(\frac{1Job}{11days}\)

Reduced efficiency as fraction of full efficiency

\(\frac{(\frac{1}{11})}{(\frac{1}{8})}=\frac{1}{11}*\frac{8}{1}=\frac{8}{11}\)

Answer D

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