Hi,

The right answer here is (D), since no solution can be determined.

Please be cautious while answering this question, so as to not miss that there are 4 different friends who paid different values, and not 3 friends who paid the same amount. It may be simple to assume that Jack, paying just 1/3rd of a given amount, is paying less than Marc, paying 2/5th of the amount. Therefore, one may be tempted to say 2/5 (40%) is greater than 1/3 (34%). But this is not the case.

This method would only be applicable if the value of the amounts paid by each of the friends was known, or was equal in a 1:1:1:1 ratio (which would make no sense). The real equations that come out are:

Jack = 1/3 (Karl+Kate+Marc)
Marc = 2/5 (Jack+Kate+Karl)
Karl = 1/4 (Kate+Marc+Jack)

None of the values are known, and therefore it is impossible to answer this question based on the information given. Hence, the answer is (D).

Since there seem to be some competing thoughts on this problem, let's take a look at an algebraic solution



Because the values in the quantities are all related to the same shared total, we can set that total = x. Therefore, using the following variables (Jack = j | Kate = k | Karl = l | Marc = m) we know that x = j + k + l + m.

Now, for Quantity A we know algebraically that j = 1/3 (x - j) because x - j is the total without Jack. Multiply the equation by 3 to eliminate the fraction to determine that 3j = x - j . Then, add j to each side to find x = 4j as our new value relating to Quantity A.

Now, for Quantity B we know that algebraically m = 2/5 (x - m) because x - m is the total without Marc. Multiply the equation by 5 to eliminate the fraction to determine that 5m = 2x - 2m . Then, add 2m to each side and divide the full equation by 2 to find 7m/2 = x as our new value relating to Quantity B.

Finally, we can relate the values for m and j directly to each other as 7m/2 = x = 4j. Simplified, 7m/2 = 4j. Multiply each side of the equation by 2 to find that 7m = 8j. Divide the equation by 7 to find that no matter what values are used, m = 8j/7 and is therefore always the greater value. So, select choice B.

Thanks! I stand corrected. I jumped to a conclusion too quickly :D

It's how those tricky GRE test makers work! Happens to all of us, but I'm glad that I had a reason to do both explanations.

Remember that most frequently there is more than one method to solving any particular GRE problem - especially Quantitative Comparisons.

Why will it have same impact on both quantity A & B? How did you deduce that?

I think the answer is B. It's clear why and the explanation you will find above, the same as mine. The question is why they bought this car. I'm curious about it, what car will buy three friends lol.. I would like my friends to contribute too, to buy a car..and drive it when going to travel. Although, this might work if you are a single man or girl. Nowadays, a married one is gonna pay from his savings for the best car even if it's a used one. As I did too but just getting a loan. It's impossible for a simple employee to buy a 2016 car, for example. That's why Money Expert Car Finance contributed to this dream of mine

Thanks, this solutions made things much more clear and better for me to understand!!!

Hi.
We do not need information for Karl, as everything is given for Jack and Marc.
(K + A (for Kate) + M)/3 = J. => K + A =3J - M
(J + K + A)2/5 = M. => K + A = 5/2M - J

3J - M =5/2M - J
4J = 7/2M
M = 8/7J
M > J
Solution B

Jack, Karl, Marc, and Kate are friends. They collected just enough money to buy a car. Jack contributed 1/3 of what his three friends contributed together. Karl contributed 1/4 of what his three friends contributed together. Marc contributed 2/5 of what his three friends contributed together.

I take smart numbers in such problems.
Since contribution amount is given in fractions so take LCM of 3,4,5 as they contributed with 1/3, 1/4 and 2/5
so LCM is 60
Now,
Jack contributed 1/3*60 = 20
Karl contributed 1/4*60 = 15
Marc contributed 2/5*60 = 24

So answer is Marc which is option B

Hello from the GRE Prep Club BumpBot!

Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.