Working together, sam and charlie can change all the light bulbs in the office building in 3 hours. it would have taken charlie
8 hours to do the job alone.which equation can be used to solve for the rate, r, for sam to change all the light bulbs in the office building by himself?
We have a work problem here. We can use our knowledge on ratio and proportion in order to set up and equation to determine what is being asked. We do as follows:
1 job / 3 hours for both = 1 job / 8 hours for charlie + 1 / x hours for sam alone
Our P = 100, r = .08, n = 1 (annually means once a year), and t = 15. Filling in accordingly, we have . Simplifying a bit gives us and . Raising that number inside the parenthesis to the 15th power gives us . Multiplying to finish means that A(t) = $317.22
. Simplifying a bit gives us 
and 
. Raising that number inside the parenthesis to the 15th power gives us 
. Multiplying to finish means that A(t) = $317.22