Question

Byron wanted to try out different water craft. He went 31 Miles downstream in a motor boat and 18 miles downstream on a jet ski. His speed in the jet ski was 10 mph faster than in the motor boat. Byron spent a total of 4 hours on the water. What was his rate of speed, in miles per hour, in the motor boat?

Answer 1

Explanation

To answer the question, we will make use of the basic relationship

$\begin{gathered} distance=speed\times time \\ time=\frac{distance}{speed} \end{gathered}$

let Bryon speed in the motorboat be x

Since his speed in the jet ski was 10 mph faster than in the motor boat, then the speed in the jet ski will be x+10

Since his total time is 4 hours then we can set up the equation

$\frac{31}{x}+\frac{18}{x+10}=4$

Our task will be to solve for x

Multiplying each term by by the lowest common multiple: (x)(x+10)

$31(x+10)+18(x)=4(x)(x+10)$

Simplifying further

$undefined$