Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

1.a=4 or-3. Two values for a and hence insuff.
2. b can be 2 or -1. Applying the values of b in a^3-a^2-b=49, we have a as either some fraction or a=4. Since a need to be an integer, a is 4.

1.a=4 or-3. Two values for a and hence insuff. 2. b can be 2 or -1. Applying the values of b in a^3-a^2-b=49, we have a as either some fraction or a=4. Since a need to be an integer, a is 4.

hence B.

Hi Venk, I see that your solution for a in statement 1 neglects the original statement which states that if sqrt(a^3 - a^2 - b) = 7, what is the value of a, You solve statement 1 independ of the original equation and that does not seem right.
At best, from the original equation we can say that
a^3 - a^2 - b = 49
Now given 1, a2-a=12 implies that 12a -b =49 from (a(a^2-a) -b =49, making statement 1 insufficient.
Statement 2 now gives you two values of b (2, -1) which when substitude into the original equation yield 2 values, one an integer of 4 and the other a non integer. Thus for a to be an integer it has to be 4. B is sufficient

how do you solve a^3-a^2-48=0 to find the value of a to conclude B as answer? S

It is posible, try picking numbers adnd you will land at a = 4 or a = 3.25.
It is easy to fall into the trap that
statement 1 combine with the original statement yields
12a -b = 49 and thus the moment one gets b, one can find a making C the dangerous answer. But if you substitue the value of B calculated and substitude into the original equation you might get only one integer for a and that is 4.

sdanquah,
I am also saying only B is sufficient. In stem 1, we have two values of 'a' - question is what is the value of 'a'. We cant conclusively say the value of 'a'. Also, when applied to the original equation, we still need 'b'. I didnt neglect it, I thought the added data is not necessary to prove insufficiency of stem 1.

sdanquah, I am also saying only B is sufficient. In stem 1, we have two values of 'a' - question is what is the value of 'a'. We cant conclusively say the value of 'a'. Also, when applied to the original equation, we still need 'b'. I didnt neglect it, I thought the added data is not necessary to prove insufficiency of stem 1.

Agreed with your answer venksume, Just that I found that you neglected orignial statement in your earlier solution.

It’s been a long time, since I posted. A busy schedule at office and the GMAT preparation, fully tied up with all my free hours. Anyways, now I’m back...

Burritos. Great, engaging session about how to network properly. How better can it get? Hosted jointly by Human Capital Club and Engineers in Management, we had a chance to...