Fraction Algebra

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 162
Joined: Sun Aug 09, 2009 4:17 pm
Location: Minnesota
Thanked: 1 times

Fraction Algebra

by EMAN » Tue Oct 13, 2009 9:48 am
I'm having a problem setting up part of this problem:



At a loading dock, each worker on a night crew loaded 3/4 as many boxes as each worker on the day crew. If the night crew has 4/5 as many workers as the day crew, what fraction of boxes loaded by the two crews did the day crew load?

(A)1/2
(B)2/5
(C)3/5
(D)4/5
(E)5/8
Source: — Problem Solving |

Master | Next Rank: 500 Posts
Posts: 371
Joined: Fri Mar 06, 2009 2:48 am
Thanked: 27 times
GMAT Score:740

by 2010gmat » Tue Oct 13, 2009 10:02 am
Lets say day crew has 100 workers
therefore night crew has 4/5 of 100 = 80 workers

say each day crew worker lifted 4 boxes .. total boxes loaded by day crew = 100*4 = 400

therefore each night crew lifted = 3/4 of 4 = 3 boxes
total no. of boxes loaded by night crew = 80*3 = 240

fraction of day/total = 400/(400+240) = 5/8

E

Master | Next Rank: 500 Posts
Posts: 399
Joined: Wed Apr 15, 2009 3:48 am
Location: india
Thanked: 39 times

by xcusemeplz2009 » Tue Oct 13, 2009 10:06 am
IMO E

let day crew no. be X and and load per worker is y;total=xy

night crew worker (4/5)x and load (3/4)y;tot = (3/5)xy

grand tot=8/5xy

day fraction=xy/(8/5)xy=5/8

OA pls
It does not matter how many times you get knocked down , but how many times you get up

Master | Next Rank: 500 Posts
Posts: 162
Joined: Sun Aug 09, 2009 4:17 pm
Location: Minnesota
Thanked: 1 times

Great

by EMAN » Tue Oct 13, 2009 1:10 pm
Great use of smart numbers. E is correct.

Legendary Member
Posts: 833
Joined: Mon Aug 04, 2008 1:56 am
Thanked: 13 times

by vivek.kapoor83 » Wed Oct 14, 2009 3:02 am
ACC to me also
Ans should be E

Shift Worker Box Total
Day 5 4 20
Night 4 3 12

Ratio 20/32 = 5/8 wht is the source...?

Master | Next Rank: 500 Posts
Posts: 162
Joined: Sun Aug 09, 2009 4:17 pm
Location: Minnesota
Thanked: 1 times

Source

by EMAN » Wed Oct 14, 2009 8:46 am
OG 12 in the Problem Solving Section is the source. Good work.

Senior | Next Rank: 100 Posts
Posts: 83
Joined: Fri May 06, 2011 9:08 am
Thanked: 5 times
GMAT Score:610

by scholardream » Tue May 01, 2012 4:29 pm
Total night crew / Total day crew = 3/4 * 4/5 = 3/5
-> Total day crew / Total 2 crew = 1 / (1+3/5) = 5/8
-> E