On a wedding catering service, An experienced chef can prepare a service for a wedding in 8 hours while an novice chef would finish the preparations in 12 hours.
If the catering service employs the same number of novice and experienced chefs, then how many chefs would it take to prepare a wedding service in 1 hour and 36 minutes?
Explain this question
(1)2
(2)3
(3)4
(4)6
(5)8
PS Caterers
This topic has expert replies

 Legendary Member
 Posts: 2330
 Joined: 15 Jan 2010
 Thanked: 56 times
 Followed by:26 members
 GMATGuruNY
 GMAT Instructor
 Posts: 15532
 Joined: 25 May 2010
 Location: New York, NY
 Thanked: 13060 times
 Followed by:1897 members
 GMAT Score:790
Let service = 24 units.mundasingh123 wrote:On a wedding catering service, An experienced chef can prepare a service for a wedding in 8 hours while an novice chef would finish the preparations in 12 hours.
If the catering service employs the same number of novice and experienced chefs, then how many chefs would it take to prepare a wedding service in 1 hour and 36 minutes?
Explain this question
(1)2
(2)3
(3)4
(4)6
(5)8
Rate for each experienced chef = w/t = 24/8 = 3 units per hour.
Rate for each novice chef = w/t = 24/12 = 2 units per hour.
Combined rate for 1 experienced chef and 1 novice chef working together = 3+2 = 5 units per hour.
To produce 24 units in 1.6 hours, rate = w/t = 24/1.6 = 15 units per hour.
Since each pair of chefs produces 5 units per hour, number of pairs needed = 15/5 = 3.
Total number of chefs in 3 pairs = 2*3 = 6.
The correct answer is D.
Mitch Hunt
Private Tutor for the GMAT and GRE
[email protected]
If you find one of my posts helpful, please take a moment to click on the "UPVOTE" icon.
Available for tutoring in NYC and longdistance.
For more information, please email me at [email protected].
Student Review #1
Student Review #2
Student Review #3
Private Tutor for the GMAT and GRE
[email protected]
If you find one of my posts helpful, please take a moment to click on the "UPVOTE" icon.
Available for tutoring in NYC and longdistance.
For more information, please email me at [email protected].
Student Review #1
Student Review #2
Student Review #3

 Senior  Next Rank: 100 Posts
 Posts: 79
 Joined: 03 Jun 2010
 Thanked: 1 times
work done by exp chef in 1 hr 1/8
work done by novice chef in 1 hr is 1/12
combined rate 1/8 + 1/12 = 5/24
now let n exp chef and n novice chef work together
combined work done in 1 hr is n/8 + n/12 = 5n/24
thus work done combined in 1.6 hrs(1 hr and 36 min) is 5n/24 *1.6 , which is equal to 1 job
therefore n= 3
total no of chefs is 2n = 6
work done by novice chef in 1 hr is 1/12
combined rate 1/8 + 1/12 = 5/24
now let n exp chef and n novice chef work together
combined work done in 1 hr is n/8 + n/12 = 5n/24
thus work done combined in 1.6 hrs(1 hr and 36 min) is 5n/24 *1.6 , which is equal to 1 job
therefore n= 3
total no of chefs is 2n = 6