Joey and Rita can individually paint a room in 8 hours. It takes Billy 12 hours to paint this same room. If all three work together, how long would it take them to paint this room?
we know that Joey and Rita paint a room in 8 hours so 100%----------> 8 hours X%----------> 1 hour x=100/8-----> 12.5% that means Joey and Rita paint 12.5% of a room in 1 hour
Billy paint a room in 12 hours so 100%----------> 12 hours X %------------> 1 hour x=100/12----> x=8.33 % that means Billy paint 8.33% of a room in 1 hour
if all three work together then All three paint (12.5%+8.33%) in 1 hour
20.83%------------> 1 hour 100%------------> x x=100/20.83-----> x=4.8 hours
