Bisi leaves 5km from school. She walks 1km at 4km/h and travels the rest of the way by bus at 16km/h. what is the average speed for the whole distance

1/2 hour

Step-by-step explanation:

I am assuming you meant "lives 5km"

The first km would take 1/4 an hour because she is going 4km/h for one hour. One hour she would go 4km but we only need 1 mile so it would be cut to a fraction.

The same fraction goes for the bus. 4 is 1/4 of 16 so you would have to add them together and have 1/2 and hour to get home.