Question 123221
You want to add their rates of working to get their
combined rate. In words:
(1 wall / 8 hours) + (1 wall / 5 hours) = 1 wall / x hours
{{{1/8 + 1/5 = 1/x}}}
multiply both sides by {{{40}}}
{{{5 + 8 = 40/x}}}
{{{13 = 40/x}}}
{{{x = 40/13}}}
{{{x = 3.076}}}hrs
{{{.077}}} hrs = {{{.077*60 = 4.62}}} minutes
So, working together, they can finish in about 3 hrs 4.6 minutes