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) m has three digits .
Hence when m = 100 m^3 has 7 digits
when m = 999 m^3 has > 7 digits.
hence not suff.

2) m^2 has 5 digits.

hence m > 100 and < 319

In both cases m^3 will have 7 digits.....
There is a shortcut....... to calculate digits..... just can't recall it now... have to hit the books in the evening.

I was wishing it would be (B) until the very last momemt while solving this. I quickly determined that ST1 is not sufficient by plaugging two simple numbers, and, based on experience, a little voice inside of me wanted to cross out the (B) answer. But since it is not the actual exam test, I decided I go ahead and solve it completely.

For the lower bound, m=100, m^3=100^3 has 7 digits.
I approximated the upper as m=315 from sqrt(99,999) (I came pretty close, the actual is m=316.) While doing (315)^3 I was parying it would not exceed 7 digits, but at the end I was wrong: it had 8 digits. So, ST2 is also not sufficient!

So, it must be (E)

That's a very good question, a challenging one for the 2 min time frame.