An engineer builds a swimming pool in her backyard that measures 7 feet x 14 feet by 4 feet deep. A mischievous child accidentally spills enough salt into the pool such that the pool water density exceeds that of freshwater by 20%. To remedy the situation, the engineer cuts two equally sized holes in the pool. Through one hole, fresh water is injected at 10 GPM, while pool water is drained through the other hole at at rate that maintains the water level in the pool at a constant depth. How long will it take for the density of water in the pool to exceed that of freshwater by only 5%