Question

Total surface area of a box of cuboid shape is 500 sq. unit. Its breadth and height is 6 unit and 5 unit respectively. What is the length of that box ?

Answer 1

Let the length of the box be l units.
Breadth of the box, b = 6 units
Height of the box, h = 5 units

Total surface area of the box = 500 square units
∴ 2(lb+ bh + hl) = 500 square units
⇒ l x 6 + 6 x 5 + 5 x l = `500/2` = 250

⇒ 6l + 30 + 5l = 250

⇒ 11l = 250 - 30 = 220

⇒ l = `220/11` = 20 units
Thus, the length of the box is 20 units.