a pipe can fill 7/10 parts of a tank in 1 hour and another pipe can fill 9/15 parts of the same tank in 1 hour. which pipe can fill the tank faster

Atreasure chest sinks at a rate no less than 20 feet er second. the floor of the icean is at most at -4,200 feet. will the tresure chest reach the ocean floor in less than 3 minutes? explain.