Question

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

• A. Rs. $456$
• B. Rs. $458$
• C. Rs. $558$
• D. Rs. $568$

Answer 1

Answer: (C)

Rs. $558$

Surface area of walls and bottom of the tank
$=2\times h\times (l+b)+lb$
$=2\times 6\times (25+12)m^2+25$ m $\times 12$ m
$=(2\times 6\times 37+25\times 12)m^2=744m^2$
$\therefore$ Cost of plastering $=$ Rs $(0.75\times 744)$
$=$ Rs. $558$