Suraj travels 124 km at a speed of 31 km/h by bus, 96 km at a speed of 16 km/h using a car, and another 105 km at 7 km/h by car. Find his average speed for the entire distance travelled.
Answer & explanation
Correct answer: option 1
Average Speed = \(\frac{Total \;Distance}{Total \;Time}\)
Distance = Speed × Time
Time= \(\frac{Distance}{Speed}\)
T1 = \(\frac{124}{31}\) = 4 hours
T2 = \(\frac{96}{16}\) = 6 hours
T3 = \(\frac{105}{7}\) = 15 hours
Total distance = 124 + 96 + 105 = 325 km
Total time = 4 + 6 + 15 = 25 hours
Average speed = \(\frac{325}{25}\) = 13 km/h
So , Average speed is 13 km/h