The time taken to fill a tank with water varies inversely as the area of cross-section of the The time taken is 40 minutes when the area is 3 cm².

1. (a)Find the number of minutes taken to fill the tank when the area is 5 cm².[2]
2. (b)It is given that the area is A square centimetres. Find the expression, in terms of A, for the number of minutes taken to fill the tank.[1]
3. (c)Water flowed into the empty tank through a pipe of area 4 cm². It flowed for 9 minutes. Find, in its simplest form, the fraction of the tank that now contained water.[1]