BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

(0.0004)(0.000005)/200,000 is equal to which of the followin

Expert replies
by Max@Math Revolution » Tue Dec 18, 2018 12:27 am

Timer

00:00

Answers

A

B

C

D

E

Stats

Difficulty

[Math Revolution GMAT math practice question]

(0.0004)(0.000005)/200,000 is equal to which of the following?

A. 10^-15
B. 10^-14
C. 10^-13
D. 10^-12
E. 10^-11
Last edited by Max@Math Revolution on Mon Dec 24, 2018 6:39 am, edited 1 time in total.
Join the discussion
Source: — Problem Solving |

by fskilnik@GMATH » Tue Dec 18, 2018 2:04 am
Max@Math Revolution wrote: (0.0004)(0.000005)/200,000 is equal to which of the following?

A. 10^-15
B. 10^-14
C. 10^-13
D. 10^-12
E. 10^-11
$$? = {{4 \cdot {{10}^{ - 4}} \cdot 5 \cdot {{10}^{ - 6}}} \over {2 \cdot {{10}^5}}} = 10 \cdot {10^{ - 15}} = {10^{ - 14}}$$

This solution follows the notations and rationale taught in the GMATH method.

Regards,
Fabio.
Fabio Skilnik :: GMATH method creator ( Math for the GMAT)
English-speakers :: https://www.gmath.net
Portuguese-speakers :: https://www.gmath.com.br
Join the discussion

by GMATGuruNY » Tue Dec 18, 2018 3:18 am
I believe that the answer choices should appear as shown below:
Max@Math Revolution wrote:[Math Revolution GMAT math practice question]

(0.0004)(0.000005)/200,000 is equal to which of the following?

A. 10^-15
B. 10^-14
C. 10^-13
D. 10^-12
E. 10^-11
The blue values below cancel out, leaving only the red values:
(4 * 10¯�)(5 * 10¯�) / (20 * 10�) = 10¯¹�/10� = 10¯¹�.

The correct answer is B.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Join the discussion

fixed

by Max@Math Revolution » Wed Dec 19, 2018 11:48 pm
=>

(0.0004)(0.000005)/200,000
= {4*5*(0.0001)(0.000001)}/{2*100,000}
= (2*10^1*10^-4*10^-6)/ (2*10^5)
= (10^-9)/(10^5) = 10^-14

Therefore, the answer is B.
Answer: B
Last edited by Max@Math Revolution on Mon Dec 24, 2018 1:09 pm, edited 1 time in total.
Join the discussion

by fskilnik@GMATH » Thu Dec 20, 2018 2:08 am
Max@Math Revolution wrote:=>

(0.0004)(0.000005)/200,000
= {4*5*(0.0001)(0.000001)}/{2*100,000}
= (2*10^1*10^-4*10^-6)/ (2*10^5)
= (10^-9)/(10^-5) = 10^-4

Therefore, the answer is B.
Answer: B
Hi, Max!

You certainly mean:

= (10^-9)/(10^5) = 10^-14

Regards,
Fabio.
Fabio Skilnik :: GMATH method creator ( Math for the GMAT)
English-speakers :: https://www.gmath.net
Portuguese-speakers :: https://www.gmath.com.br
Join the discussion

by Max@Math Revolution » Mon Dec 24, 2018 1:10 pm
fskilnik@GMATH wrote:
Max@Math Revolution wrote:=>

(0.0004)(0.000005)/200,000
= {4*5*(0.0001)(0.000001)}/{2*100,000}
= (2*10^1*10^-4*10^-6)/ (2*10^5)
= (10^-9)/(10^-5) = 10^-4

Therefore, the answer is B.
Answer: B
Hi, Max!

You certainly mean:

= (10^-9)/(10^5) = 10^-14

Regards,
Fabio.
You are right. The solution and choices are fixed.
Thank you for your comments.
Join the discussion

by Scott@TargetTestPrep » Sun Mar 10, 2019 6:46 pm
Max@Math Revolution wrote:[Math Revolution GMAT math practice question]

(0.0004)(0.000005)/200,000 is equal to which of the following?

A. 10^-15
B. 10^-14
C. 10^-13
D. 10^-12
E. 10^-11
Using scientific notation, we have:

(4 x 10^-4)(5 x 10^-6)/(2 x 10^5)

(2 x 10^-4)(5 x 10^-6)/10^5

(10^1 x 10^-10)/10^5

10^-9/10^5 = 10^-14

Answer: B

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Join the discussion