GMAT Test M14 Master Thread - All discussions

\((125.4 - \frac{12}{5}) = 124.4 - 2.4 = 122\) . 34% of 122 is a little more than \(\frac{122}{3} = 41\) . Among the listed choices, C is the closest.

Am I mistaken or did it change from 125.4 to 124.4 incorrectly? I think the answer is the same but there might be something wrong with the explanation.



che,
dg

You are correct - there is a 124 instead of 125 in the explanation. That will be fixed.
Thank you.

1 Jack is painting twice as fast as Tom.
2 If Tom painted twice as fast as he actually does, the brothers would finish the work in 3 hours
Explanation:
Statement (1) by itself is sufficient. S1 reduces to equation 1/J + 1/(2J) = 1/4, where J denotes the time it takes Jack to paint the wall alone. From this equation J=6
Statement (2) by itself is sufficient. S2 reduces to equation: 1/J + 2*(1/4 – 1/J) = 1/3 ; J=6
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When you say Jack painted twice as fast as Tom it means - Toms time is double or rate is 1/2 - explanation for 1 is fine.
When you move on to 2: If Tom painted twice as fast as he actually did - maintaining the same symbology as in statement 1, statement 2 should be
1/J + 1/2(1/4-1/J) = 1/3. (With this equation you dont get a unique solution using statements 1 and 2 individually).
I understand 1/J and (1/4-1/J )are rates and twice as fast means work is done in half the time or at double the rate. It would have been nice if the problem statement/solution were consistent !

Problem statement seems open ended.
A 5 meter long wire is cut into two pieces. If the longer piece is then used to form a perimeter of a square, what is the probability that the area of the square will be more than 1 if the original wire was cut at an arbitrary point?

I agree with the explanation given in the solution, but there can be infinite points in the first or the last 1 meter. I mean you can cut it at 0.1,0.11,0.2....similarly on the other side you can cut it at 4.1,4.11,4.12,4.13 etc. If I were the problem-setter I would put in a rider/statement that in someway restricts the number of favorable outcomes.