Aboat travels 26 miles up the river in the same amount of time it takes to travel 46 miles down the same river. if the current is 5 miles per hour, what is the speed of the boat in still water?

Awater holding tank measures 105 m long, 50 m wide, and 8 m deep. traces of mercury have been found in the tank, with a concen- tration of 60 mg/l. what is the total mass of mercury in the tank? answer in units of kg.