Question

$\text{A box made of sheet metal costs Rs6480 at Rs120 per square metre. If the box is 5m long and 3 m wide, find, its height.}$

Answer 1

Cost if metal sheet = surface area of the box * rate

6480 = 120 * surface area of the box

surface area of the box = 54 $m^2$

2(lb+bh+hl) = 54

2(5*3+3h+5h) = 54

30 + 16h = 54

16h = 54-30
h = 24/16 = 1.5m