Question

A man goes to Jaipur from Surat at a speed of 3km/hr and returns to Surat at speed of 15km/hr, through same route. What is his average speed (in km/hr) of the entire journey?

• A. 5
• B. 8
• C. 6
• D. 1

Answer 1

Answer:

A. 5

For a round trip with equal distances, the average speed is given by:

$\text{Average Speed} = \frac{2xy}{x + y}$

Where
( x = 3 ) km/hr and ( y = 15 ) km/hr

$\text{Average Speed} = \frac{2 \times 3 \times 15}{3 + 15}$
$= \frac{90}{18}$
= 5

Answer: 5 km/hr