It is currently 19 Nov 2017, 13:20

### 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

# Mike has to take 5 tests containing 80 questions each. After

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
CEO
Joined: 21 Jan 2007
Posts: 2734

Kudos [?]: 1076 [0], given: 4

Location: New York City
Mike has to take 5 tests containing 80 questions each. After [#permalink]

### Show Tags

03 Nov 2007, 16:24
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Mike has to take 5 tests containing 80 questions each. After completing four tests, Mike has an average of 80 percent of correct answers. What is the least number of questions Mike needs to get right in the ffth test to bring his average to 82%?

70
72
75
78
80

Kudos [?]: 1076 [0], given: 4

Current Student
Joined: 03 Oct 2006
Posts: 84

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

### Show Tags

03 Nov 2007, 16:31
B 72

I'm sure there's a simple equation, but I did this piece meal.

80% of 80 = 64
64 * 4 = 256 correct answers on 4 tests

82% of (80 * 5) = 328

328-256 = 72

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

Senior Manager
Joined: 04 Jun 2007
Posts: 364

Kudos [?]: 110 [0], given: 0

Re: Easy Avg question [#permalink]

### Show Tags

03 Nov 2007, 16:33
bmwhype2 wrote:
Mike has to take 5 tests containing 80 questions each. After completing four tests, Mike has an average of 80 percent of correct answers. What is the least number of questions Mike needs to get right in the ffth test to bring his average to 82%?

70
72
75
78
80

320*80%= 256 right
400*82%= 328 right
he needs to get another 328-256= 72 questions right

Kudos [?]: 110 [0], given: 0

Director
Joined: 11 Jun 2007
Posts: 909

Kudos [?]: 291 [0], given: 0

Re: Easy Avg question [#permalink]

### Show Tags

03 Nov 2007, 16:37
bmwhype2 wrote:
Mike has to take 5 tests containing 80 questions each. After completing four tests, Mike has an average of 80 percent of correct answers. What is the least number of questions Mike needs to get right in the ffth test to bring his average to 82%?

70
72
75
78
80

another approach:

80% * 4 = 320
82% * 5 = 410
so we know he as to get 90% on his 5th test

.9*80 = 72

Kudos [?]: 291 [0], given: 0

CEO
Joined: 29 Mar 2007
Posts: 2553

Kudos [?]: 528 [0], given: 0

Re: Easy Avg question [#permalink]

### Show Tags

03 Nov 2007, 20:20
bmwhype2 wrote:
Mike has to take 5 tests containing 80 questions each. After completing four tests, Mike has an average of 80 percent of correct answers. What is the least number of questions Mike needs to get right in the ffth test to bring his average to 82%?

70
72
75
78
80

.8(320)/320=.8

256+X/400=.82

328=X+256
x=72

B

Kudos [?]: 528 [0], given: 0

Re: Easy Avg question   [#permalink] 03 Nov 2007, 20:20
Display posts from previous: Sort by

# Mike has to take 5 tests containing 80 questions each. After

 post reply Question banks Downloads My Bookmarks Reviews Important topics

Moderator: chetan2u

 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®.