The bus drove for the first 9 km on the way at a speed of 44 km / h. The second 24 km at a speed

The bus drove for the first 9 km on the way at a speed of 44 km / h. The second 24 km at a speed of 54 km / h. What is its average bus speed.

Vav = S / t

Let’s calculate the entire route of the bus: 9 + 24 = 33 km.

Let’s find the time during which the bus traveled the first 9 km: t = S / V; 9:44 = 9/44 hours.

Find the time for which the bus traveled the second 24 km: 24: 54 = 24/54 = 4/9 hours.

Find the entire time of the bus: 9/44 + 4/9 = (81 + 176) / 396 = 257/396 hours.

Find the average speed of the bus: 33: 257/396 = 257/12 = 21 5/12 km / h.