Question

Dwayne starts at the surface of the water and swims to -25 feet. From there he swims +10 feet to see the fish and then back down -5 feet to the seaweed. How many feet does dewayne need to swim in order to get back to the surface

Answer 1

(-25) + 10 + (-5) = -20 feet is his current position. To reach zero, he should add 20 feet to his altitude.