The number of tests that the group should buy?

This topic has expert replies
Legendary Member
Posts: 641
Joined: 14 Feb 2012
Thanked: 11 times
Followed by:8 members
Hello,

Can you please assist with this:

A paleontological research group in Montana is purchasing two types of disposable fossil testing kits for its upcoming dig. Fossil Ease brand tests cost $20 each, and Dino Diagnosis brand tests cost $30 each. The group wants to spend an equal amount of money on each type of test.

In the table below, identify the number of tests that the group should buy from Fossil Ease and from Dino Diagnosis so that the group spends an equal amount of money on each type of test. Make only one selection in each column.


Fossil Ease Dino Diagnosis
100
150
200
250
400


OA: Fossil Ease : 150 Dino Diagnosis: 100

I tried to take the lcm of 20 and 30 i.e. 60 but I don't think this is the right approach.


Thanks for your help,
Sri

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10347
Joined: 23 Jun 2013
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:508 members
GMAT Score:800

by [email protected] » Sat May 10, 2014 4:14 pm
Hi Sri,

You absolutely had the right idea, you just have to take it a step further.

We're told that the two tests cost $20 and $30 AND that we want to spend an EQUAL AMOUNT of money on each.

The LCM of 20 and 30 is 60, so imagine if you spent $60 on each test....

You'd get 3 Fossil Ease Tests and 2 Dino Diagnosis Tests.

This gives us a RATIO of what the correct answer has to be.....3:2

Now, pick two numbers from the given options that end in a 3:2 ratio...

Final Answer: [spoiler]FE = 150, DD = 100[/spoiler]

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image

Legendary Member
Posts: 641
Joined: 14 Feb 2012
Thanked: 11 times
Followed by:8 members

by gmattesttaker2 » Sat May 10, 2014 5:11 pm
[email protected] wrote:Hi Sri,

You absolutely had the right idea, you just have to take it a step further.

We're told that the two tests cost $20 and $30 AND that we want to spend an EQUAL AMOUNT of money on each.

The LCM of 20 and 30 is 60, so imagine if you spent $60 on each test....

You'd get 3 Fossil Ease Tests and 2 Dino Diagnosis Tests.

This gives us a RATIO of what the correct answer has to be.....3:2

Now, pick two numbers from the given options that end in a 3:2 ratio...

Final Answer: [spoiler]FE = 150, DD = 100[/spoiler]

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

Hi Rich,

Thanks a lot for the explanation.

Best Regards,
Sri

Newbie | Next Rank: 10 Posts
Posts: 1
Joined: 22 Jan 2015

by riakhan » Thu Jan 22, 2015 10:15 pm
ok thanks gmattesttaker2




_________________________________________________
https://www.passguide.us/
www.uca.es
www.hw.ac.uk
Last edited by riakhan on Mon Feb 09, 2015 11:16 pm, edited 1 time in total.

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10347
Joined: 23 Jun 2013
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:508 members
GMAT Score:800

by [email protected] » Mon Jan 26, 2015 10:56 pm
Hi riakhan,

Welcome to the Forums. An old IR post seems like an odd place to post your first message, but that's okay. How have your studies been going? And when are you planning to take the GMAT?

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image