percentage

[gmatkkvinu]

The amount of work in a leather factory is increased by 50%. By what per cent is it necessary to increase the number of workers to complete the new amount of work in previously planned time, if the productivity of the new labour is 25% more.
a.60%
b 66.66%
c.40%
d.33.33%
e.80%

[Brent@GMATPrepNow]

The amount of work in a leather factory is increased by 50%. By what per cent is it necessary to increase the number of workers to complete the new amount of work in previously planned time, if the productivity of the new labour is 25% more.
a.60%
b 66.66%
c.40%
d.33.33%
e.80%

We can solve this by plugging in some nice numbers.

We're told that the productivity of the new labour is 25% more.
So, let's say the current workers can produce 4 units/day, which means the new workers can produce 5 units/day.

Let's also say that there are currently 100 workers.

So, 100 workers producing 4 units/per day can produce a total of 400 units.

We're told that the work is increased by 50%.
50% of 400 is 200, so the factory must now produce 600 units.

The current 100 workers are producing 400 units/per day, so the new workers must produce the remaining 200 units.
Since the new workers produce 5 units/day, we'll need need 40 new workers.

In other words, we need to increase the workforce from 100 to 140, which represents an increase of [spoiler]40%[/spoiler]

Answer: C

Cheers,
Brent

[sanjoy18]

Lets Amount work is 100 units now it is 150

now for time being imagine new and old worker have equal productivity

lets 2 worker earlier work 100 units
in the same time I need 3 worker to complete 150 units in earlier time
therefore number worker has increased by 50%..
But it is given that new worker are 25% more productive..now i am certain that %increase muse be less than 50%..so A,B and E are out..
Now at this some one can calculative guess.

To get the final answer:

I know from above that if i have n worker with 100% efficient then i need n/2 additional worker
But since new worker are 25% more efficient then number of new worker let say x must be less than n/2
therefore x/(n/2)= 100/125
>>x= (2/5)*n >> hence 40% increase

[Java_85]

It's much easier to solve this question with substituting numbers instead of writing equations. I agree with 40% too.

[JAI SINGH]

HEY PLEASE TELL ME ON WHICH EXAM THIS QUESTION ASKED ...SEND ME THAT PAPER ON [email protected]

[[email protected]]

Hi JAI SINGH,

This prompt is a poorly-worded GMAT-style question. If you're studying for the GMAT, then it would be best for you to use Official GMAT material (such at the OG13/GMAT2015, the subject-specific books for Quant and Verbal and the software from www.mba.com) and any materials from any credible GMAT Training Companies.

GMAT assassins aren't born, they're made,
Rich