A box made of sheet metal costs `6480`at `120`per square metre.If the box is `5m` long and `3m` wide,find its height

Answer

1.5 m

Explanation

Area of sheet metal `= ("total cost")/("cos per "m^(2)) = (6480)/(120) m^(2) = 54 m^(2)`
`2(lb + bh + lh) = 54 rArr 2(5 xx 3 + 3h + 5h) = 54`
`rArr 16h = (54 - 30) = 24 rArr h = (24)/(16)m = (3)/(2)m = 1.5 m`