It takes Tom 4 hours to paint the fence and it takes his brother, Bobby 8 hours to paint the same fence. how long would it take thaem to paint the fence together

Question

It takes Tom 4 hours to paint the fence and it takes his brother, Bobby 8 hours to paint the same fence.  how long would it take thaem to paint the fence together

bme89 · Answer

2.66 hours.  Can someone confirm?  Tom paints at 0.25 fences/hour, Bobby at 0.125 fences/hour.  Together at 0.375 fences/hour.  (1 fence)/(0.375 fences/hour) = 2.66 hours

anonymous · Answer

working together they paint 3/8 of fence in 1 hour 
so whole fence takes 8/3 - 2 2/3 hors or 2 hours 40 minutes

anonymous · Answer

correct bme

anonymous · Answer

thanks