A liquid flows through a capillary viscometer in 45 s at 25 °C. Under the same conditions, water requires 15 s. If the viscosity of water at 25 °C is 0.89 cP and the densities of the two liquids are nearly identical, what is the approximate viscosity of the unknown liquid?
a) 0.30cP
b) 2.7cP
c) 3.0cP
d) 1.8cP