GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 22 Oct 2019, 13:20

Close

GMAT Club Daily Prep

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.

Close

Request Expert Reply

Confirm Cancel

The half-life of a radioactive element is defined as the amount

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
CR Forum Moderator
avatar
V
Joined: 25 Apr 2018
Posts: 637
GMAT 1: 680 Q49 V34
Reviews Badge CAT Tests
The half-life of a radioactive element is defined as the amount  [#permalink]

Show Tags

New post 04 Feb 2019, 08:42
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

68% (01:33) correct 32% (01:37) wrong based on 37 sessions

HideShow timer Statistics

The half-life of a radioactive element is defined as the amount of time required for the amount of the element to decrease by half. If the half-life of an element is 3 years, how long will it take for the element to be reduced to one-eighth of its original amount?

A. 3 years

B. 9 years

C. 21 years

D. 24 years

E. 27 years

_________________
Please give kudos if you found my posts helpful!

Project CR Butler - 2 CR's everyday
Senior Manager
Senior Manager
User avatar
P
Status: Gathering chakra
Joined: 05 Feb 2018
Posts: 435
Premium Member
Re: The half-life of a radioactive element is defined as the amount  [#permalink]

Show Tags

New post 04 Feb 2019, 09:15
I think this is a disguised population problem:

1 HL --> 50% or 1/2
2 HL --> 25% or 1/4
3 HL --> 12.5% or 1/8

If each half life is 3 years, then 3 HL = 9, B
Director
Director
avatar
G
Joined: 09 Mar 2018
Posts: 994
Location: India
Re: The half-life of a radioactive element is defined as the amount  [#permalink]

Show Tags

New post 04 Feb 2019, 09:28
gmat1393 wrote:
The half-life of a radioactive element is defined as the amount of time required for the amount of the element to decrease by half. If the half-life of an element is 3 years, how long will it take for the element to be reduced to one-eighth of its original amount?

A. 3 years

B. 9 years

C. 21 years

D. 24 years

E. 27 years


1/2 in 3 years (given)

1/4 in 6 years

1/8 in 9 years

B
_________________
If you notice any discrepancy in my reasoning, please let me know. Lets improve together.

Quote which i can relate to.
Many of life's failures happen with people who do not realize how close they were to success when they gave up.
Target Test Prep Representative
User avatar
D
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8129
Location: United States (CA)
Re: The half-life of a radioactive element is defined as the amount  [#permalink]

Show Tags

New post 06 Feb 2019, 20:07
gmat1393 wrote:
The half-life of a radioactive element is defined as the amount of time required for the amount of the element to decrease by half. If the half-life of an element is 3 years, how long will it take for the element to be reduced to one-eighth of its original amount?

A. 3 years

B. 9 years

C. 21 years

D. 24 years

E. 27 years


If the amount of the element starts at 1 gram, then after 3 years, it will be at 1/2 gram, then after 6 years it will be at 1/4 gram, and finally, after 9 years, it will be at 1/8 gram.

Answer: B
_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
TTP - Target Test Prep Logo
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

GMAT Club Bot
Re: The half-life of a radioactive element is defined as the amount   [#permalink] 06 Feb 2019, 20:07
Display posts from previous: Sort by

The half-life of a radioactive element is defined as the amount

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne