Matt and Jaron are constructing a brick wall. If they work together, each at his own constant rate, how many hours does it take for them to finish the wall?

(1) Matt lays 3 bricks for every 2 that Jaron lays --> the ratio of the rates is 3 to 2. Not sufficient.

(2) There are 1000 bricks in the wall. Clearly insufficient.

(1)+(2) If Matt and Jaron lay 3 and 2 bricks respectively in 1 second the answer would be 200 seconds but if Matt and Jaron lay 3 and 2 bricks respectively in 1 hour the answer would be 200 hours. Not sufficient.

Answer: E.
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Can you explain how (1) just gives us the ratio of rates?

We need to determine how many hours it will take for Matt and Jaron to construct a wall.

Statement One Alone:

Matt lays 3 bricks for every 2 that Jaron lays.

Since we cannot fully determine the rate of Matt or Jaron, and since we do not know how many bricks make up the wall, statement one is not sufficient to answer the question.

Statement Two Alone:

There are 1000 bricks in the wall.

Since we do not have the rates of either Matt or Jaron, statement two is not sufficient to answer the question.

Statements One and Two Together:

Using the information in statements one and two, we still cannot answer the question.

If Matt’s rate was 3 bricks per hour and Jaron’s was 2 per hour, then it would take 1,000/5 = 200 hours to complete the job. However, if Matt’s rate was 6 bricks per hour and Jaron’s was 4 per hour, then it would take 1,000/10 = 100 hours to complete the job.

Answer: E
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