Question

A bus traveled on a level road for 3 hours at an average speed 20 miles per hour faster than on winding road. The time spent on the winding road was 3 hours. Find the average speed of the level road if the entire trip was 330 miles

Answer 1

Step 1:

Given data

On a winding road

Average speed = x

Time = 3hours

`\begin{gathered} \text{Distance travelled = Average sp}eed\text{ }*\text{ Time} \\ =\text{ 3x miles} \end{gathered}`

On Level road

Average speed = 20 + x

Time = 3 hours

`\begin{gathered} \text{Distance travelled = Average sp}eed\text{ }*\text{ Time} \\ =\text{ 3(20 + x)} \\ =\text{ 60 + 3x miles} \end{gathered}`

Step 2:

Total distance traveled = 330 miles

`\begin{gathered} 3x\text{ + 60 + 3x = 330} \\ 6x\text{ + 60 = 330} \\ 6x\text{ = 330 - 60} \\ 6x\text{ = 270} \\ x\text{ = }(270)/(6) \\ x\text{ = 45 miles/hour} \end{gathered}`

Final answer

Average speed of the level road = x + 20 = 45 + 20 = 65 miles per hour

Average speed of the level road = 65 miles