SOLUTION: tom can paint a room in 5 hours, steve can paint the same room in 10 hours and Mary can paint the same room in 20 hours. If they work together, how long will it take them to paint
Hi
Let x represent time in hours together
Question state***per hour being the equalizer
1/5 + 1/10 + 1/20 = 1/x |multiplying thru with 20x so as all denominators = 1
4x + 2x + x = 20
7x = 20
x = 20/7 hrs, time in hours together