To travel trip of 40 miles?the speed for the first Y miles : PS Archive
Check GMAT Club App Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 11 Dec 2016, 03:23

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# To travel trip of 40 miles?the speed for the first Y miles

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
CEO
Joined: 15 Aug 2003
Posts: 3460
Followers: 67

Kudos [?]: 855 [0], given: 781

To travel trip of 40 miles?the speed for the first Y miles [#permalink]

### Show Tags

22 Sep 2003, 13:19
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

1.To travel trip of 40 miles?the speed for the first Y miles was
X, and the speed for the remaining 40-y is 1.2X. what's the average
speed?
1) x=12 m/h 2) y=20

2.The 'rule of 72', defining the time needed for the investment to
double, is K/2, where K means the percentage interest to be
compounded yearly. If an investment of $10,000 is invested at the annual rate of 8%. And after the investment yields to be$20,000, and
again be invested at the annual rate of 12%. Then according to the
'rule of 72', how long will it take the original to yield a total of
\$40,000?
SVP
Joined: 03 Feb 2003
Posts: 1603
Followers: 8

Kudos [?]: 236 [0], given: 0

### Show Tags

22 Sep 2003, 21:18
(2) 10 years to transform 10000 into 40000.
GMAT Club Legend
Joined: 15 Dec 2003
Posts: 4302
Followers: 39

Kudos [?]: 420 [0], given: 0

### Show Tags

16 Jan 2004, 18:17
For Q2, the answer should be 15 years. The question is wrong. Rule of 72 should be '72/interest rate' for an investment to double. You can try it yourself on your calculator. Therefore, at 8%, it will take 72/8 = 9 years for first portion to double. Then 72/12 = 6 years to double again at 12%. Then 9+6 = 15 years.

Quote:
Q2 - is it 4+6 = 10 ?
Besides it doesn't make sense that at 8% interest, it takes only 4 years to double as opposed to 6 years when interest rates are at 12%.
_________________

Best Regards,

Paul

Manager
Joined: 26 Dec 2003
Posts: 227
Location: India
Followers: 1

Kudos [?]: 3 [0], given: 0

### Show Tags

16 Jan 2004, 18:37
10 yrs , 4 yrs from 10,000 to 20,000 and 6 yrs from 20,000 to 40,000
SVP
Joined: 30 Oct 2003
Posts: 1793
Location: NewJersey USA
Followers: 5

Kudos [?]: 97 [0], given: 0

### Show Tags

16 Jan 2004, 18:38
This is a wierd question.
I just did k/2 to arrive at the result.
However at 1.08 interest rate it takes 9 years and at 12 % interest rate it takes approx 6 years to double the money.

I had to use log function in my calculator you know.

Praetorian should post the answer. I guess he ( I assume it is he ) has posted so many Qs and may be does not have enough time to go through his mail and see each response.

Hi paul,
You pretty much get to the page I am in a matter of couple of days. Looks like you are beating your head on Quant section now. Good luck to you anyway.
[#permalink] 16 Jan 2004, 18:38
Display posts from previous: Sort by

# To travel trip of 40 miles?the speed for the first Y miles

 post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group and phpBB SEO Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.