Question 1029454
Working alone, Alexia can dig a 68 cubic foot hole in 8 hours.
 Working together, Alexia and Brandon can dig a 100 cubic foot hole in 6 hours and 15 minutes. Working alone, how long would it take Brandon to dig 50 cubic feet. How long in hours? How long in hours and minutes?
:
Find how many cu/ft that Alexia can dig in 1 hr: 
{{{68/8}}} = 8.5 cu/ft per hr
:
Find how many cu/ft that Alexia and Brandon can dig in 1 hr
{{{100/6.25}}} = 15.38 cu/ft per hr
Then
15.3846 - 8.5 = 6.8846 cu/ft per hr Brandon digging alone
:
" Working alone, how long would it take Brandon to dig 50 cubic feet.
 How long in hours?
{{{50/6.8846}}} = 7.2626 hrs
How long in hours and minutes?
7 + .2626(60) = 7 hrs 15.75 min