The employees at a lumberyard produce 12ft. planks of wood, which are

Question

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The employees at a lumberyard produce 12ft. planks of wood, which are then cut into 2ft. planks. If Jake can cut through a 12ft. plank six times per minute and Mary can cut through a 12ft. plank four times per minute, then working non-stop, how long would it take Jake and Mary to cut 10,000 12ft. planks into 60,000 2ft. planks?

A. 3.3 days
B. 3.5 days
C. 3.8 days
D. 4.2 days
E. 4.8 days

gmatophobia · Answer

Jake can cut a 12ft plank six times per min, So in one min Jake produces 7 planks each of which is 2ft.

Mary can cut a 12ft plank four times per min, So in one min Jake produces 5 planks each of which is 2ft.

Working together they can produced 12 planks each of which is 2ft.

We are required to find the time required (in days) to produce 60,000 planks

Time required =  \frac{60000}{ 12 * 60 * 24}

Time required =  \frac{1000 }{ 12 * 24}

We know that 100 / 25 equals to 4.

So, 1000 / 24, will be slightly more than 40.

IMO B

DZ3 · Answer

To cut a 12ft. plank into 2ft. pieces the plank has to be cut 5 times.

Therefore, Jake cuts planks at rate of  \frac{6}{5}  per minute while Mary cuts  \frac{4}{5}  of a plank per minute.

Both working together cut at a rate of  \frac{10}{5}  = 2 planks per minute or 2,880 planks per day.

\frac{10,000}{2,880}  equals roughly 3.5

IMO B.

ShaikhMoice · Answer

A's speed 6 cuts per minute
B's speed 4 cuts per minute
Together 10 cuts per minute

Time needed to cut 60000 pieces 60000/(10*60*24) = 4.1666 or 4.2

Answer is D

okHedwig · Answer

I can understand here Jake when cuts 6 times per min, produces 7 nos of 2ft planks. But mary cuts 4 times per minute, so Mary will only be able to produce 4 nos of 2ft planks.
So, as per calculation, no of days = 60000/(11*60*24) which comes equivalent to 3.9 or C.
Can you please explain how B is the answer here?

Bunuel · Answer

The question is not precise. Ignore.

The employees at a lumberyard produce 12ft. planks of wood, which are

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