Radius (r_{1}) of upper end of container = 20 cm

Radius (r_{2}) of lower end of container = 8 cm

Height (h) of container = 16 cm

Slant height (l) of frustum =

Capacity of container = Volume of frustum

Cost of 1 litre milk = Rs 20

Cost of 10.45 litre milk = 10.45 × 20

= Rs 209

Area of metal sheet used to make the container

= π (20 + 8) 20 + π (8)^{2}

= 560 π + 64 π = 624 π cm^{2}

Cost of 100 cm^{2} metal sheet = Rs 8

Cost of 624π cm^{2} metal sheet = (624 x 3.14 x 8)/100

=156.75

Therefore, the cost of the milk which can completely fill the container is

Rs 209 and the cost of metal sheet used to make the container is Rs 156.75.