Question

A person has to cover a distance of 8 km in 1 hour. If he covers one-fourth of the distance in one-third of the total time, then what should his speed (in km/h) be to cover the remaining distance in the remaining time so that the person reaches the destination exactly on time?

• A. 6
• B. 8
• C. 9
• D. 7

Answer 1

Answer:

C. 9

Total distance = 8 km
Total time = 1 hour

First part

Distance covered = $( \frac{1}{4} \times 8 = 2 ) km$
Time taken = $( \frac{1}{3} \times 1 = \frac{1}{3} )$ hour

Remaining

Remaining distance = ( 8 - 2 = 6 ) km
Remaining time = $( 1 - \frac{1}{3} = \frac{2}{3} )$ hour

Required speed

$\text{Speed} = \frac{6}{2/3} = 6 \times \frac{3}{2} = 9$

Final Answer:

9 km/h