WORK

heshamelaziry wrote:Two carpenters, Antoine and Ben, built identical picture frames at different constant rates. Antoine, working alone for 7 hours, built some of the picture frames in a given shipment; then Ben, working alone for 6 hours, built the rest of the picture frames in the shipment. How many hours would it have taken Antoine, working alone, to build all of the picture frames in the shipment?

1. Antoine built one picture frame every 15 minutes.

2. Antoine built four times as many picture frames in 7 hours as Ben built in 6 hours


OA B

So, the question tells us that Antoine built "some" in 7 hours, and then B built the rest of them in 6 hours.

Statement One:

Antoine built one picture frame every 15 minutes.

But without knowing how many picture frames there are, this info is not helpful. Insufficient.

Statement Two:

So, Antoine does four out of five parts of the whole job in 7 hours. This info will allow us to compute how long it would take Antoine do the whole job. Sufficient.

Choose B.

Note that because this is data sufficiency we wouldn't actually perform the math in analyzing statement two; instead, we would realize that we COULD perform it.

Here is the work we would not have had to do:

Because Antoine does 4/5 of the job in 7 hours, it will take Antoine 7* (5/4) = 35/4 or 8 and 3/4 hours to complete the whole job working alone.