How to solve

Ascuba diver was 80 feet below sea level and swam up at a rate of 4 feet per minute. the two solutions show how long it took the scuba diver to reach an elevation of 20 feet below sea level. lydia and max used the methods shown below to find the time it took the diver to reach the new elevation.

Which expression is equivalent to sq-80

Water flows at a steady rate from a tap. its takes 40 seconds to fill a 4 litre watering can from the tap. the rate at which water flows from the tap is halved. complete: 4 litres into cm3