SOLUTION: 60 workers complete a project in 40 days. For the project to be completed in 20 days, how many additional workers are needed if each new worker is only half as productive as the or

Algebra ->  Rate-of-work-word-problems -> SOLUTION: 60 workers complete a project in 40 days. For the project to be completed in 20 days, how many additional workers are needed if each new worker is only half as productive as the or      Log On


   

Question 996822: 60 workers complete a project in 40 days. For the project to be completed in 20 days, how many additional workers are needed if each new worker is only half as productive as the original group?
Answer by josgarithmetic(39613) About Me  (Show Source):
You can put this solution on YOUR website!
FIXED MISTAKE.

r, the rate of any one of the original workers;
r/2, the rate of any one of the additional workers;
n, the number of the additional workers;

Not this,system%2860r%2A40=1%2Ccross%28n%28r%2F2%29%2A20=1%29%29;
But THIS: system%2860r%2A40=1%2C%2860r%2Bn%28r%2F2%29%29%2A20=1%29

The equality to 1 is for "one whole piece of work or job".

This is a uniform work rates problem exercise. There are two unknown variables used in a system of two equations. Work to understand the basic concept and how the variables are used with this concept and the system of equations shown. When you understand this, you should have no trouble solving the system for both n and r.