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.

13 km/h

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