Question

Maria can fill a certain order in 13 hours and Jim needs 15 hours to do the same job. Working together, how long will it take them to fill the order?

Answer 1

Answer:

7 hours

Step-by-step explanation:

Maria can fill a certain order in 13 hours,

so her working rate is

$\frac{1}{13}$

and Jim needs 15 hours to do the same job, so his working rate is:

$\frac{1}{15}$

Assuming the two will take x hours working together, then

$\frac{1}{13} + \frac{1}{15} = \frac{1}{x}$

$\frac{28}{195} = \frac{1}{x}$

$x = \frac{195}{28}$

$x = 6.96$

It will take both approximately 7 hour