in the 2002 HSC Q7 b
A cooler, which is initially full, is drained so that at time t seconds the volume of
water V, in litres, is given by
V=25(1-t/60)^2 for 0<t<60
i) how much water was intially in cooler?
answer - 25 litres
ii)After how many seconds was the cooler one-quarter...