Gopal travels from A to B at the speed of 5km/h, from B to C at 10 km/h, and from C to D at 15 km/h. If AB = BC = CD, then find Gopal’s average speed.
Explanation:
Let AB = BC = CD = 30 kms
Time taken from A to B = 30/5 = 6 hours. Time taken from B to C = 30/10 = 3 hours. Time taken from C to D = 30/15 = 2 hours.
∴ Total time taken = 6 + 3 + 2 = 11 hours. Total distance travelled = 90 kms
Average speed = 90/11 = 8(2/11) kmph.
Hence, option (a).