A tank is 25m long 12m wide and 6m deep. The cost of plastering its walls and bottom at 55 paise per sq m is	Choose the correct option.
A) Rs. 209.20	B) Rs. 309.20	C) Rs. 409.20	D) Rs. 509.20	E) None of these
Explanation:   Area to be plastered = [2(l + b) Ã— h] + (l Ã— b)   = [2(25 + 12) Ã— 6] + (25 Ã— 12) = 744 sq m   Cost of plastering = 744 Ã— (55/100) = Rs. 409.20 Answer: Rs. 409.20
<result>C</result>
A tank is 25m long 12m wide and 6m deep. The cost of plastering its walls and bottom at 55 paise per sq m is