It is currently 18 Mar 2018, 08:42

### 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

# Events & Promotions

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

# A racetrack bounded by two concentric circles, one with a diameter of

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

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 44293
A racetrack bounded by two concentric circles, one with a diameter of [#permalink]

### Show Tags

18 Feb 2018, 23:12
Expert's post
3
This post was
BOOKMARKED
00:00

Difficulty:

65% (hard)

Question Stats:

50% (00:58) correct 50% (01:54) wrong based on 56 sessions

### HideShow timer Statistics

A racetrack bounded by two concentric circles, one with a diameter of 160 yards and the other with a diameter of 140 yards, is to covered with asphalt. If the asphalt layer is to be 1 foot deep, how many cubic yards of asphalt will be needed? (1 yard = 3 feer)

(A) $$75\pi$$

(B) $$90\pi$$

(C) $$500\pi$$

(D) $$1500\pi$$

(E) $$2000\pi$$
[Reveal] Spoiler: OA

_________________
examPAL Representative
Joined: 07 Dec 2017
Posts: 210
Re: A racetrack bounded by two concentric circles, one with a diameter of [#permalink]

### Show Tags

18 Feb 2018, 23:18
1
This post received
KUDOS
Expert's post
1
This post was
BOOKMARKED
Bunuel wrote:
A racetrack bounded by two concentric circles, one with a diameter of 160 yards and the other with a diameter of 140 yards, is to covered with asphalt. If the asphalt layer is to be 1 foot deep, how many cubic yards of asphalt will be needed?

(A) $$75\pi$$

(B) $$90\pi$$

(C) $$500\pi$$

(D) $$1500\pi$$

(E) $$2000\pi$$

Since the calculation required is straightforward, we'll just do it.
This is a Precise approach.

We need to calculate the area between the two circles and multiply it by a height of 1 foot = 1/3 yard.
This is $$\pi *80^2 - \pi*70^2 = 6400 \pi - 4900 \pi = 1500 \pi$$.

(C), 1500/3 = 500 is our answer
_________________

David
Senior tutor at examPAL
Signup for a free GMAT course

We won some awards:

Join our next webinar (free)
Save up to \$250 on examPAL packages (special for GMAT Club members)

Intern
Joined: 12 Feb 2018
Posts: 4
Re: A racetrack bounded by two concentric circles, one with a diameter of [#permalink]

### Show Tags

05 Mar 2018, 06:44
1
This post received
KUDOS
Bunuel please edit the question if you have time. This kind of question in gmat provides always the convesion between the units feet- yards
Math Expert
Joined: 02 Sep 2009
Posts: 44293
Re: A racetrack bounded by two concentric circles, one with a diameter of [#permalink]

### Show Tags

05 Mar 2018, 07:17
Mikimix wrote:
Bunuel please edit the question if you have time. This kind of question in gmat provides always the convesion between the units feet- yards

Done. Thank you.

Check other Conversion problems to practice in Special Questions Directory.
_________________
Re: A racetrack bounded by two concentric circles, one with a diameter of   [#permalink] 05 Mar 2018, 07:17
Display posts from previous: Sort by

# A racetrack bounded by two concentric circles, one with a diameter of

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

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