Question

A runner has to cover a distance of 100 km. After running for 5 hours and 20 minutes, he finds that he has completed 2/3rd of the total distance. What is his speed in km/h?

• A. 12.5 km/h
• B. 17.5 km/h
• C. 16.25 km/h
• D. 15.5 km/h

Answer 1

Answer:

A. 12.5 km/h

Total distance = 100 km

Distance covered in 5 hours 20 minutes:

$\frac{2}{3}\times 100=\frac{200}{3}\text{ km}=66\tfrac{2}{3}\text{ km}$

Time:

$5\text{ h }20\text{ min}=5+\frac{20}{60}=5+\frac{1}{3}=\frac{16}{3}\text{ h}$

Speed:

$\text{Speed}=\frac{\text{Distance}}{\text{Time}}$
$=\frac{\frac{200}{3}}{\frac{16}{3}}$

$=\frac{200}{16}$

$=12.5\text{ km/h}$

Answer:$(\boxed{12.5\ \text{km/h}})$