days

Hi sgr21,

Since we have two people working on a job together, this is a perfect opportunity to use the "work formula"

Work Formula = (AxB)/(A+B)

We're told:
A = 48 days to do a job
B = B days to do a job
Together = 12 days to do a job

So, let's plug in…

48B/(48+B) = 12

48B = 12(48+B)
4B = 48 + B
3B = 48
B = 16

Now we know that B takes 16 days to do the job.

We're told that B gets injured and now works at HALF his efficiency, so instead of taking 16 days, he takes 32 days.

So we have:
A = 48
B = 32

Plug in….

(48x32)/(48+32) = 96/5 = 19.2

Rounding to the nearest Day (as instructed), we get answer A

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