Answer:
The answer to the question is
The actual duration of the trip is 8/9 times the normal duration or the bus arrived 1/9 times earlier than it would have at a constant speed of v kph
Step-by-step explanation:
Speed of bus in the first third distance = v kph
Speed of bus for the remaining two thirds = 1.2 v kph
To solve the question, we note that speed = distance/time
therefore time = distance/speed
Let the distance of the destination be D, then
Normal duration at speed v = D/v
Actual duration (D/3)÷v + (2D/3)÷(1.2v) ⇒ (1.2*D/3 + 2D/3)1.2v
= = (8/9)×D/v
Therefore the actual duration is 8/9 times the normal duration