You are going to make a box out of cardboard. The box needs to measure 10 cm by 5 cm by 5 cm; 10% of the final product will be wasted in the cutting process. How much cardboard do you need?

Multiple choice answers are:

125 cm.
140 cm.
200 cm.
250 cm.
275 cm.

4 answers

I'll be glad to check your answer.
surface area of a six sided box:

10x5*2+5x5*2+10x5*2

which is 250. So you need the excess added,

Amount-waste=250
.9amount=250
amount=about 278cm^2

check: 278*.9=250

I wonder if the box is supposed to have a lid, I put that in the calculations.
"10x5*2+5x5*2+10x5*2"

waste amount=25 (10% of 250)

250+25=275
alx is correct. it does say 25 percent of the final product, not as I read 25 percent of the material used...