Question

A submarine at a depth of -2 2/3 feet descended 5 1/2 feet. How many feet must the submarine rise to reach the surface? Explain your thinking.

Answer 1

Original position of the submarine below the Surface = -2 2/3= -8/3

Submarine at a depth of -2 2/3 feet descended by 5 1/2 feet.

So new position of the Submarine = $\frac{-8}{3}-\frac{11}{2}\\\\ = \frac {-16 - 33}{2}\\\\ = \frac{-49}{6}$

To Reach the surface submarine must rise = 0-(-49/6)

As seen from the equation the two negative sign [(-)(-)] will change into a positive sign.

At the surface the position of the submarine = +49/6 feet