Question

Worker A works at a constant rate and, working alone, can complete a job in 6 hours. Worker B works at a constant rate and, working alone, can complete the same job in 5 hours. Worker C works at a constant rate and, working alone, can complete the same job in 3 hours.

Answer 1

Answer:

$R= \frac{1job}{1.429 hours}$

So then we will have that the 3 working together will complete 1 job in approximately 1.429 hours for this case.

Explanation:

If we want to express the situation in math terms and find the number of hours that takes to complete 1 job with the 3 at the same time, we can do this.

For this case we have the following rates:

$R_A =\frac{1job}{6hours}$

$R_B =\frac{1 job}{5 hours}$

$R_C=\frac{1job}{3 hours}$

And we know that working together the rate would be the addition of the rates like this:

$R=R_A +R_B +R_C = \frac{1job}{6hours}+\frac{1job}{5hours}+\frac{1job}{3hours} =\frac{7 jobs}{10hours}$

And if we divide the numerator and denominator by 7 we got:

$R= \frac{1job}{1.429 hours}$

So then we will have that the 3 working together will complete 1 job in approximately 1.429 hours for this case.