Mr. Bundda travels in this car and covers 1/4 part of his journey with 8 km/h, 3/5 part with 6 km/h and remaining 3/20 part with a speed of 10 km/h. Find out his average speed during the whole journey.
Correct Answer: 6.83 km/h
Explanation:
According to the average speed formula,
P = 1/4, Q =3/5, R = 3/20
x = 8 km/h, y = 6 km/h, z = 10km/h
∴ Required average speed = 1 / [(P/x) + (Q/y) + (R/z)]
=1 / [(1/32) + (1/10) + (3/200)]
= 1/[(25 + 80 + 12)/800]
= 800/117
= 6.83 km/h