Question

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:
a. Rs 456. b. Rs458
c. Rs558. d. Rs568

Answer 1

$\Longrightarrow{\boxed{\bold{Answer: Option\:(C)}}}$

$\textbf{\underline{Step-by-step explanation :- }}$

➣ Lateral surface area of cuboid

= 2( l + b )h

= 2( 25 + 12 )m × 6 m

= 444 m²

➣ Area of base = length × breadth

= 25 m × 12 m

= 300 m²

➣ Total area needed to be plastered :-

= 444 m² + 300 m²

= 744 m²

✍️ ✍️ ✍️ ✍️ ✍️ ✍️ ✍️ ✍️ ✍️

➣ Now, cost of plastering 1 m²

= 75 p or Rs 75/100

➣ Cost of plastering 740 m²

= 744 × 75/100

$\textbf{\huge{= \underline{Rs 558}}}$

$\textsf{\underline{\red{Hence Option (C) is correct}}}$

Answer 2

Rs. 558 .....................