A tank is 25 m long, 12 m wide and 6 m deep. The cost of plastering its walls…
2025
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
Attempted by 7 students.
Show answer & explanation
Correct answer: C
Solution:
Compute the bottom area.
Bottom area = length × width = 25 × 12 = 300 m².
Compute the area of the four walls.
Two walls of size 25 × 6: 2 × (25 × 6) = 2 × 150 = 300 m².
Two walls of size 12 × 6: 2 × (12 × 6) = 2 × 72 = 144 m².
Total walls area = 300 + 144 = 444 m².
Total area to be plastered = bottom + walls = 300 + 444 = 744 m².
Cost per m² = 75 paise = Rs. 0.75. Total cost = 744 × 0.75 = Rs. 558.
Final answer: Rs. 558.