Question

11) A boat traveled 336 miles downstream and back. The trip downstream took 12 hours. The trip back took 14 hours. What is the speed of the boat in still water? What is the speed of the current? Give answer through the elimination method.

Answer 1

The speed of the boat in still water is 26 miles.

The speed of the current is 2 miles

Solution :

speed of a boat when it goes downstream is
`336/12 = 28 mi/h`

speed of a boat when it goes upstream is
`336/14 = 24 mi/h`

Let v is speed of the boat in still water and x is speed of the current. Then,

`v + x = 28`

`v - x = 24`

Solve the system for v and x and get v = 26 mi/h, x = 2 mi/h.

Hence The speed of the boat in still water is 26 miles and

the speed of the current is 2 miles