If 3 brick masons can complete the front of one house in 12 days, how many days will it take 16 brick masons, working at the same rate, to complete the fronts of 60 identical houses?
The problem shows that since the masons work at the same rate each Mason covers a third of the front of the house in four days. This means that it does 1/12 of the front in one day. Using this, we see that 16 brick masons will finish one and one third of a house in a day. 60/(4/3) = 45 days.