Water fl ows through a cylindrical pipe of radius 0.74 cm. It fills a 12 litre bucket in 4 minutes.
When the 12 litre bucket is emptied into a circular pool, the water level rises by 5 millimetres. Calculate the radius of the pool correct to the nearest centimetre.
a) 11 cm
b) 14 cm
c) 17 cm
d) 20 cm