The population of 8 villages is 900, 750, 1100, 1050, 835, 1250, 555, and 630. Find the population of Ninth village if the average population of Nine villages is 900.
A car that gets 15 miles per gallon of gasoline can travel 250 miles on a full tank. If the same car got 20 miles per gallon, how many miles could it travel on a full tank?
If a pipe can fill a tank in 2 hours and another pipe can fill the same tank in 40 minutes. how much time in minutes is needed to fill the tank if both the pipes are working together?