Question 404619
Computer A can carry out a task in 6 hours.  Computer B can do the same task in 4 hours.  How long would it take it they did it together?
.
Let x = time (hours) it takes for both
then
x(1/6 + 1/4) = 1
multiplying both sides by 24:
x(4 + 6) = 24
10x = 24
x = 2.4 hours
or
x = 2 hours and 24 minutes