NEW HERE? LEARN MORE
closeclose
Last visit was: 25 Apr 2024, 12:08 It is currently 25 Apr 2024, 12:08
Decision Tracker
My Rewards
New posts
New comers' posts

Close
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
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

If Kyle works alone, he can wash the night shift dishes in 55 minutes.

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92914
Own Kudos [?]: 618998 [1]
Given Kudos: 81595
Send PM
CAT Tests Forum Quiz Mode
If Kyle works alone, he can wash the night shift dishes in 55 minutes. [#permalink] New post   14 Jul 2020, 03:54
1
Kudos
Expert Reply
00:00
A
B
C
D
E

Difficulty:

5% (low)

Question Stats:

93% (01:55) correct 7% (02:04) wrong based on 56 sessions
Hide Show timer Statistics
If Kyle works alone, he can wash the night shift dishes in 55 minutes. It will only take him 40 minutes if he works, together with Harry. How long will it take Harry to wash the night shift dishes by himself?

A. 65
B. 87
C. 95
D. 147
E. 165
ShowHide Answer
Official Answer
D
User avatar
L
yashikaaggarwal
Senior Moderator - Masters Forum
Joined: 19 Jan 2020
Posts: 3137
Own Kudos [?]: 2769 [1]
Given Kudos: 1510
Location: India
Schools: Cranfield (A) Warwick MiM "23 (M)
GPA: 4
WE:Analyst (Internet and New Media)
Send PM
Re: If Kyle works alone, he can wash the night shift dishes in 55 minutes. [#permalink] New post   14 Jul 2020, 07:45
1
Kudos
If Kyle works alone, he can wash the night shift dishes in 55 minutes. It will only take him 40 minutes if he works, together with Harry.
So,
Let Harry complete work in x minutes
And they do 1/55 & 1/x work in 1 minute
1/55 + 1/x = 1/40
(X+55)/55x = 1/40
40X+2200 = 55x
2200 = 15X
X = 146.666
Or X = 147

Answer is D

Posted from my mobile device
User avatar
G
VERBAL1
Manager
Manager
Joined: 18 Jun 2020
Posts: 180
Own Kudos [?]: 140 [0]
Given Kudos: 151
Location: India
Concentration: Marketing, Sustainability
Schools: Cass '21 LBS '22 Cambridge '22
Send PM
Re: If Kyle works alone, he can wash the night shift dishes in 55 minutes. [#permalink] New post   14 Jul 2020, 11:02
Kyle's rate: 55 minutes
Rate of work together: 40 minutes
Harry's rate : h

using the combined rates formula :ab/ a+ b........ 55h/ 55+ h=40
solving for h, we get h=146.66

OA: D. 147
User avatar
G
TestPrepUnlimited
Tutor
Joined: 17 Sep 2014
Posts: 1251
Own Kudos [?]: 938 [0]
Given Kudos: 6
Location: United States
GMAT 1: 780 Q51 V45
GRE 1: Q170 V167
Send PM
Re: If Kyle works alone, he can wash the night shift dishes in 55 minutes. [#permalink] New post   14 Jul 2020, 16:31
Expert Reply
Bunuel wrote:
If Kyle works alone, he can wash the night shift dishes in 55 minutes. It will only take him 40 minutes if he works, together with Harry. How long will it take Harry to wash the night shift dishes by himself?

A. 65
B. 87
C. 95
D. 147
E. 165


Notate K and H as their efficiencies.

Translating the information gives K = 1/55 and K + H = 1/40.

55 = 5*11 and 40 = 5*8, their LCM is 5 * 8 * 11.

H = 1/40 - 1/55 = \(\frac{11}{440} - \frac{8}{440}\) = \(\frac{3}{440}\).

However this is his efficiency, the amount of time needed is 1/H = 440/3 which is a little smaller than 150.

Ans: D
GMAT Club Bot
gmatclubot
Re: If Kyle works alone, he can wash the night shift dishes in 55 minutes. [#permalink]
14 Jul 2020, 16:31
Moderators:
Bunuel
Math Expert
92914 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions