Target Test Prep 20% Off Flash Sale is on! Code: FLASH20

Redeem
Target Test Prep
5-Day Free Trial
5-day free, full-access trial TTP

Available with Beat the GMAT members only code

MORE DETAILS
Target Test Prep
Magoosh
Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

MORE DETAILS
Magoosh

Which of the following is closest to

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 am
Location: Las Vegas, USA
Thanked: 19 times
Followed by:37 members

Which of the following is closest to

by Max@Math Revolution » Tue Feb 20, 2018 11:58 pm
[GMAT math practice question]

Which of the following is closest to $$11^5*9^5-7*10^7?$$

$$A.\ 10^2$$
$$B.\ 10^7$$
$$C.\ 10^8$$
$$D.\ 10^9$$
$$E.\ 10^{10}$$
Top
User avatar
Elite Legendary Member
Posts: 3991
Joined: Fri Jul 24, 2015 2:28 am
Location: Las Vegas, USA
Thanked: 19 times
Followed by:37 members

by Max@Math Revolution » Fri Feb 23, 2018 1:20 am
=>

Since 11 is close to 10 and 9 is close to 10, 11^5*9^5 is close to 10^5*10^5 = 10^10.
Since 7*10^7 is a relatively small number compared with 10^10, 11^5*9^5 - 7*10^7 is approximately equal to 10^10.

Therefore, the answer is E.
Answer: E
Top
Post new topic Post Reply
• Page 1 of 1