Question

The cost of polishing 35 identical wooden cubical boxes at the rate of rs. 20 per sq. cm is rs. 1,51,200. Find the edge of each cubical box​

Answer 1

Answer: 6 cm

Explanation:

Total surface area of cubical box =
`6a^2` , a= edge length of cube (i)

As per given ,

Total surface area of one box =
`\frac{\text{Cost of polishing}}{\text{Rate} *\text{Number of boxes}}`

`=(151200)/(20*35)\\\\=(151200)/(700)\\\\= 216\ sq. cm` (ii)

Now from (i) and (ii) ,

`6a^2 = 216\\\\\Rightarrow\ a^2= 36\\\\\Rightarrow\ a= 6 \text{ [By taking square root on both sides]}`

Hence, the edge of each cubical box​ = 6 cm.