The angle of minimum deviation for a prism of refractive index 1.5 is equal to the angle of the prism. The angle of the prism is (cos 41° = 0.75)
a.62°
b.41°
c.82°
d.31°
8 litres are drawn from a cask full of wine and is then filled with water. This operation is performed three more times. The ratio of the quantity of wine now left in cask to that of water is 16 : 65 . How much wine did the cask hold originally?
a.18 litres
b.24 litres
c.32 litres
d.42 litres