Question

The volume of a closed cubical tank is 1331 cubic metres. Find the cost of painting its complete surface area from outside at the rate of ₹ 10 per square meter.

• A. 7260
• B. 7240
• C. 7000
• D. 7280

Answer 1

The correct option is A

7260

Let the side of the given cubical tank be 'a' metres .

Volume of the given cube is $a\times a\times a$

By prime factorization, we get cube root of 1331 as 11

Surface area of each side of a cube is $a\times a$

Total surface area of the cube is $6\times a\times a$

Cost incurred is then $10\times 6\times 11\times 11$ = ₹ 7260