SOLUTION: The number of cars manufactured on an assembly line varies jointly as the number of workers and the time they worked. If 120 workers can produce 60 cars in 2 hours, find how many c

Algebra.Com
Question 1045246: The number of cars manufactured on an assembly line varies jointly as the number of workers and the time they worked. If 120 workers can produce 60 cars in 2 hours, find how many cars 140 workers should be able to produce in 3 hours?
Found 2 solutions by Boreal, ikleyn:
Answer by Boreal(15235)   (Show Source): You can put this solution on YOUR website!
C=k*W*t
60=k*120*2
60/240=k
k=(1/4)
C=(1/4)*140*3
=(1/4)*420=105 cars.
Answer by ikleyn(52781)   (Show Source): You can put this solution on YOUR website!
.
The number of cars manufactured on an assembly line varies jointly as the number of workers and the time they worked.
If 120 workers can produce 60 cars in 2 hours, find how many cars 140 workers should be able to produce in 3 hours?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 

To solve such a simple problem, it is better to use the conception of "rate of work"

Rate of work in the first case is

.

It is "how many cars can one worker produces in one hour".

Rate of work in the second case is 

.

The rate of work is assumed to be constant, or the same, in both cases.
This assumption is equivalent to "The number of cars manufactured on an assembly line varies jointly as the number of workers and the time they worked."

By equating two quantities for the rate-of-work, you get the equation (like proportion)

 = .

Find x from this proportion.

x =  = 105.

Answer. 105 cars.

For similar problems, see the lesson
    - Rate of work problems
in this site.

Also, you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.


RELATED QUESTIONS

The number of cars manufactured on an assembly line varies jointly as the number of... (answered by mukhopadhyay)
The number of cars produced at a General Motors assembly plant’s assembly line varies... (answered by TimothyLamb,josmiceli)
Suppose that the number of cars manufactured at an automobile plant varies jointly as the (answered by JulietG)
The number of cars varies jointly as the number of workers and the hours they work. If... (answered by jorel1380)
The number of calculators produced in a certain company varies jointly as the number of... (answered by ankor@dixie-net.com)
In country​ A, about five times as many cars are manufactured per day than in... (answered by jorel1380)
In country​ A, about threethree times as many cars are manufactured per day... (answered by greenestamps)
In country​ A, about four times as many cars are manufactured per day than in country... (answered by josgarithmetic)
In country​ A, about five times as many cars are manufactured per day than in country... (answered by math_tutor2020,ikleyn)