A technician can install a television transmission line in 5 h , and his helper can install it in 5 hours 18 minutes 22 seconds. How many hours will it take the

Question

A technician can install a television transmission line in 5 h , and his helper can install it in 5 hours 18 minutes 22 seconds. How many hours will it take them to do it working together?

Answer 1

First let's convert the second time interval to hours in decimal form:

5 hrs. + 18min/(60 min per hour) + 22 sec./(3600 sec. per hour) = 5.30611 hrs.

 

Combine the two rates and multiply by "t" and set to "1 installation":

[(1 installation)/(5 hrs.) + (1 installation)/(5.30611 hrs.)]*t = 1 installation

 

So, t = 1/(5^-1 + 5.30611^-1), using a calculator: t = 2.574 hours.