Chapter 12, Problem 83CLR

To determine

To find: The number of hours that the Roberto could have paddled.

Answer to Problem 83CLR

The time that Roberto could paddle is $6\text{hr}$ .

Explanation of Solution

Given:

The distance paddled by Roberto is twice as many hours as Edward and Jim Paddled for one hour.

The time taken is less than of ten hours when the three men paddled.

Calculation:

Consider the number of hours Edward paddled is $x$ . Then the number of hours paddled by Roberto is $2x$ hours.

Consider the number paddled by Jim is less than $1\text{hr}$ . Then three of them paddled less than ten hour and the interval is,

  $\begin{array}{l}2x+x+1<10\\ 3x+1<10\\ x<\frac{9}{3}\\ x<3\end{array}$

Thus, the number of hours that the Roberto could paddle is,

  $\begin{array}{l}2x<3\cdot 2\\ 2x<6\end{array}$

Thus, the time that Roberto could paddle is $6\text{hr}$ .