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 m2. Find the total surface area of cold storage.
(a) 1222.5
(b) 1282.5
(c) 1333.3
(d) 1285.5
Sol:
Given: The length of cold storage is 5 times its breadth, and its height is 8 m
The area of its four walls (including the doors) is 720 m2
Concept Used:
TSA of cuboid = 2(lb + bh + lh) TSA = Total surface area, l = length, b = breadth, h = height
Calculation:
⇒ According to the question
⇒ 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
Therefore, the total surface area of cold storage is 1282.5 m2
