Question

From the given data, find the average speed of Jack (in km/hr).

• A. 4.34
• B. 4.43
• C. 52/12
• D. 13/3

Answer 1

Answer: (A), (C), (D)

The correct options are
A

4.34

C

52/12

D

13/3

Speed is generally given in km/hr e.g., 50 km/hr, which can also be represented as $\frac{50km}{1hr}$

We can derive an equation for the speed as

Speed =$\frac{Distance}{Time}$

$\begin{array}{cccc}Day& Distance& Time& Speed=\frac{Distance}{Time}\\ Monday& 2km& 0.5hr& \frac{2km}{0.5hr}=4km/hr\\ Tuesday& 2km& 0.4hr& \frac{2km}{0.4hr}=5km/hr\\ Wednesday& 2km& 0.5hr& \frac{2km}{0.5hr}=4km/hr\end{array}$

Average Speed = $\frac{\text{4 km/hr + 5 km/hr + 4 km/hr}}{3}$ = $\frac{13}{3}km/hr=\frac{52}{12}km/hr=4.33km/hr$