A tank is 25m long 12m wide and 6m deep. The cost of plastering its walls and bottom at 75 paise per sq m is

Area to be plastered =  $2l+b\times h+l\times b$ 

= $225+12\times 6+25\times 12=744sq.m$ 

Cost of plastering =  $744\times \frac{75}{100}=Rs.558$