Manonamission wrote:

At a loading dock, each worker on the 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 all the boxes loaded by the

two crews did the day crew load?

(A) 1/2

(B) 2/5

(0 3/5

(D) 4/5

(E) 5/8

Note : Apologies for the typo error in the initial Q. Modified numbers in red.

Hi,

Let the number of workers in day be x and each loads y boxes, so total is x*y....

While in night, the workers are 4/5*x and each loads 3/4*y, so total = 4x/5 * 3y/4= 3xy/5....

TOTAL= xy + 3/5* xy =8/5*xy..

Fraction day workers loads xy/(8/5)xy=5/8..

E..

The other way is of course take some numeric value for each, but these values should be multiples of the denominator to avoid confusion....

So day worker should be 4 or its multiple and # of day workers be 5...

Day workers load 4*5=20..

Ni workers load 3/4*4*4/5*5=3*4=12..

So TOTAL=12+20=32..

Fraction of day work=20/32=5/8

_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372

2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

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