if it took 9 hours to mow 15 lawns, then at that rate, how many lawns could be mowed in 27 hours? What was the rate of lawns mowed per hour

What is the product? (x2+3y+7) [yy+1)

Aremote-controlled boat can travel at 4 feet per second in calm water. the boat traveled 48 feet with the current, and then it traveled 16 feet against the current in the same amount of time. how fast is the current?

At noon a tank contained 10cm water. after several hours it contained 7cm of water. what is the percent decrease of water in the tank?