A snowstorm causes a bus driver to decrease the usual average rate along a 300-mile route by 5 miles per hour. As a result, the bus takes three hours longer
than usual to complete the route. At what average rate does the bus usually
cover the 300-mile route?

How many liters of peroxide should be added to 12 liters of an 8% peroxide solution so that the resulting solution contains 16% peroxide?   original added new amount of peroxide 0.96 liters x 0.96 + x amount of solution 12 liters x 12 + x 0.18 liter 1.14 liters 1.92 liters 2.10 liters