RRB NTPC CBT I 10 Jan 2021 Shift 2 Paper

A water tank is made of an aluminum sheet 3 cm thick. The tank is open at the top. Its external dimensions are 1.36 m, 1.06 m, and height 0.83 m. What is the cost of painting the inner surface of the tank at 50 paise per 100 sq. cm?