Rates Answers

1. (a) 72 km/hr (b) 12 km/litre

2. (a) 10 km/hr (b) 5 rev/min (c) 4 g/cm3

3. (a) 10 cm/hr
(b) 

(c) -10

4. (a) 12, 27, 48

(b) 

(c) The area increases more rapidly as the radius increases.