A tank is 25m long 12m wide and 6m deep. The cost of plastering its walls and bottom at 70 paise per sq m is  Select the correct option:
A) rs . 258.80
B) rs . 358.80
C) rs . 458.80
D) rs . 520.80
E) none of these

Rationale: "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 — ( 70 / 100 ) = rs . 520.80 answer : d"
Answer: D