The length of a cold storage is 5 times its breadth, and its height is 8 m. The area of its four walls (including the doors) is 720 cm2. Find the total surface area of cold storage.
Answer & explanation
Correct answer: option 4
We know that,
TSA of cuboid = 2(lb + bh + lh)
We have,
The length of cold storage = 5 times its breadth,
Height = 8 m
The area of its four walls = 720 m2 (Doors included)
So,
= l = 5b, h = 8
= Area of four walls = 2(lh) + 2(bh)
= 720 = 2(5b × 8) + 2(b × 8)
= 720 = 80b + 16b
= 720 = 96b
= b = 7.5 m,
l = 5b = 5 × 7.5 = 37.5 m
TSA = 2(lb + bh + lh) = 2(37.5 × 7.5 + 7.5 × 8 + 8 × 37.5)
= 2(281.25 + 60 + 300) = 2(641.25) = 1282.5