Jane makes toy bears. When she works with an assistant, she makes 80

Question

Jane makes toy bears. When she works with an assistant, she makes 80 percent more bears per week and works 10 percent fewer hours each week. Having an assistant increases Jane’s output of toy bears per hour by what percent?

A. 20%
B. 80%
C. 100%
D. 180%
E. 200%

A. 20% 
B. 80%
C. 100% 
D. 180% 
E. 200%

LuisP · Answer

Let's assume she made 100 bears in 10 hours, that is 10/h
She now makes 180 bears in 9 hours, that is 20/h

Thus, I'd choose C

AS7x · Answer

C.

Let's assume just Jane 40 bears per 40/hrs a week, so that is 1 bear/hr. With an assistant she makes 72 bears per 36 hours a week or 2 bears/hr (  /  ).

* 100% = 100%

NagrajB · Answer

We can use fractional equivalents here to solve the problem

80% = 4/5; this means that in 1st case if she prepares 5 bears, in 2nd case she prepares 9 bears
10% = 1/10; this means that in 1st case if she needs 10 hours, in 2nd case she needs 9 hours

Now we come to productivity
Based on above fractional values the productivity in 1st case is 0.5 bears / hour and in the 2nd case it is 1 bear / hour
Hence the productivity is double with the assistant i.e. the increase in productivity is 100%

singhabhijeet · Answer

Condition 1: Jane working alone:

Let's say Jane works 50 hrs/ week and make 100 bears.   
 
toys produces in 1 hr =  \frac{100}{50}  = 2 ------------------- eq 1

Condition 2: Jane + Assistant working together:  
 
Hrs worked Jane = 45    
Toys produced = 180

Toys produced in 1 hr =  \frac{180}{45}  = 4 ------------------- eq 2

% change =  \frac{{Change In Value}}{{Original Value }}  * 100

=> % change =  \frac{{4-2}}{2}  * 100

=> 100%

Ans: C

pushpitkc · Answer

I would assume numbers to do this question

If the  number of toy bears, Jane makes in a week are 1000  and  she has to work 10 hours  to do it.
Since, she makes 80% more toy bears per week and works 10% less hours to do the work with the assistant's help
 The number of toy bears will be 1800  and  the number of hours worked are 9.

So, previously she made 100 bears per hour(1000/10) and now she makes 200 bears/hour (1800/9)
This is an increase of 100%(Option C)

shashankism · Answer

Let Jane makes x bears in t hours
Per hour Jane makes x/t bears.

with assistant Jane makes (1+0.8) = 1.8 x bears in (1-0.1) = 0.9t hours
Per hour Jane makes 1.8x/0.9 t = 2x/t bears

So increase in Jane's output per hour = (2x/t - x/t) *100/(x/t) = 100%

shashankism · Answer

In actual GMAT we should solve it by taking numbers. 
Lets say Jane makes 100 bears in 10 hours
So in 1 hour Jane makes 10 bears

With assistant, Jane makes 100x1.8 = 180 bears in 10x0.9 = 9 hours 
So in 1 hours Jane makes 180/9 = 20 bears

Increase in Jane's output = (20-10)/10 = 100%

JeffTargetTestPrep · Answer

work = rate × time

Since “80 percent more” corresponds to a factor of 1.8, we have:

w_2 = 1.8w_1

r_2 × t_2 = 1.8 × r_1 × t_1

Since “10 percent fewer” corresponds to a factor of 0.9, we have:

r_2 × (0.9 × t_1) = 1.8 × r_1 × t_1

Thus,

r_2/r_1 = 1.8/0.9 = 2

Since a factor of 2 corresponds to “100% percent greater,” having an assistant increases Jane’s output per hour by 100%.

Answer: C

luisdicampo · Answer

Deconstructing the Question

Output increases by  80% . 
Hours decrease by  10% . 
Productivity = Output / Hours. 
We must find the percent increase in productivity.

Step-by-step

Assume original output =  100 
Assume original hours =  100

Original productivity:

\frac{100}{100} = 1

With assistant:

Output:

100 \rightarrow 180

Hours:

100 \rightarrow 90

New productivity:

\frac{180}{90} = 2

Increase from 1 to 2 is:

100\%

Answer: 100%

Jane makes toy bears. When she works with an assistant, she makes 80

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Jane makes toy bears. When she works with an assistant, she makes 80

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