Question

A motorboat has a four hour supply of gasoline. How far from the marina can it travel if the rate going out against the current is 20mi/h and the rate coming back with the current is 30 mi/h

Answer 1

Answer:

The distance the marina can travel = $x_{}$ = 48 miles

Step-by-step explanation:

The rate going out against the current is = u - v = 20 $\frac{mi}{h}$

The rate going out with the current is = u + v = 30 $\frac{mi}{h}$

Let the distance traveled by the motorboat = $x_{}$

Total time the boat can travel = 4 hours

⇒ Total time = ( Time taken by boat to go against the current ) + ( Time                                  taken by boat to go  with the current )

⇒ 4 = $\frac{x}{u - v} + \frac{x}{u + v }$

⇒ 4 = $\frac{x}{20} + \frac{x}{30}$

⇒ 4 = $\frac{x}{12}$

⇒ $x_{}$ = 48 miles

This is the distance the marina can travel.