Problem Solving

Hi Vincen,

When dealing with exponents in questions such as these, it's important to understand the 'magnitude' of each power and the meaning of the differences in the values.

For example 10^3 and 10^2 might 'look' similar, but they're really not "close":
10^3 = 1,000
10^2 = 100
10^3 - 10^2 = 900... meaning that the difference of those two numbers is actually far closer to 10^3 than you might initially realize. The same idea applies to this prompt.

11(10^10) - 4(10^4)

11(10^10) is 110,000,000,000
4(10^4) is 40,000

The difference of those numbers is 109,999,960,000, which is relatively close to 10^11

Final Answer: E

GMAT assassins aren't born, they're made,
Rich

Vincen wrote: ↑

Sun Sep 10, 2017 12:20 pm

Which of the following is the closest to 11*10^10-4*10^4 ?

A. 10^2
B. 10^7
C. 10^8
D. 10^9
E. 10^11

OA is E.

What are the calculus to determine the correct answer?

Since 4*10^4 is relatively small when compared to 11*10^10, then the difference would still be close to 11*10^10, which is approximately 10*10^10 = 10^11.

Answer: E