1. (a) 25 km/h

(b) 57 km/h

(c) 48 km/h

2. (a) 3.23 hours or 3 hours and 14 minutes (to nearest minute)

(b) 4.5 hours

(c) 10 seconds

3. (a) 1440 km

(b) 35 km

(c) 498.75 km

4. 440 km and an average speed of 88 km/h