Problem Solving

Princeton Cracking the GMAT, Question 21 in Math BIN 4. I think this is where mnjoosub got this question.

The book gives the formula for Cubbys Weight as C= p/4 +A

SO basically, Princeton review put this question in the wrong section, definately should have gone in the Verbal section of the book as a Sentence Correction problem, being that it cleary states Brian AND Cubby...

Hi Friends,

I am back after some break.

The question is from Princeton Bin 4- No 21.

The question seem confusing at first, but after analysis, we can notice that the verb 'weights' goes with Cubby but not Brian and Andrea (More of a SC question than PS ).

So, C=A+(p/4).

I made the same mistake at first and did not get the answer.

I put this question on the forum just to boost some thinking.

Conclusion:

Whether Maths or Verbal be cautious with wording :!: :roll:

Just the fact the B+C=p/4 + A does not work for any of the answers .. resovles the mystry of the word smithy .. (Brian and Andrea's) dog .. or Brian and (Andrea's dog ..)

I think C= p/4 + A is logical in this case .. given the choices.
;p

Many replies. A little confused.

mnjoosub wrote:Together, Andrea and Brian weigh p pounds; Brian weighs 10 pounds more than Andrea. Brian and Andrea's dog, Cubby, weighs p/4 pounds more than Andrea. In terms of p, What is Cubby's weight in pounds?

(A) (p/2)-10
(b) (3p/4)-5
(c) (3p/2)-5
(d) (5p/4)-10
(e) (5p)-5

The OA is B.

I can get the answer by plugging, but I would like to have the mathematical explanation.

Thanks.

The problem seems to be with interpretation of the information, in particular the phrase:

Brian and Andrea's dog, Cubby, weighs p/4 pounds more than Andrea.

Most people are interpreting this as "the sum of Brian and Andrea's dog is p/4 pounds more than Andrea".

However, when I first read it, I interpreted it as "the dog belonging to Brian and Andrea weighs p/4 pounds more than Andrea does".

I'm 100% certain that my interpretation is correct (and not just by reverse engineering the question from the answer).

We have to remember that math questions will be gramatically correct. Let's look at the verb in the sentence.

"Weighs" is a singular verb. In order for the first interpretation to be right, the sentence would have had to read:

Brian and Andrea's dog, Cubby, WEIGH p/4 pounds more than Andrea

since "Brian and Cubby" form a plural noun and require a plural verb.

So, now that we know how to interpret the question, our equations are:

A + B = P

B = A + 10

C = A + P/4

We want to solve for C, so let's get rid of A and B by getting A in terms of P and then subbing into the Cubby equation:

A + 10 = B

A + A + 10 = P

2A = P - 10

A = P/2 - 5

C = P/2 - 5 + P/4

C = (2P/4) + P/4 - 5

C = (2P + P)/4 - 5

C = 3P/4 - 5

Choose (b).

I will go with B too.