Question

A plastic box $1.5m$ long, $1.25m$ wide and $65cm$ deep is to be made. It is to be open at the top Ignoring the thickness of the plastic sheet, find
(i) the area of the sheet required for making the box.
(ii) the cost of sheet for it if a sheet measuring $1sqm$ costs Rs.$20$

Answer 1

Dimensions: $1.5$m $\times 1.25$m $\times 0.65$m

(i) Area of sheet required for making the box

$=$TSA$-$upper face area

$=2(1.5\times 0.65+1.5\times 1.25\times 1.25\times 0.65)-(1.5\times 1.25)$

$=5.45m^2$

(ii) Cost $=5.45\times 20$

$=$Rs. $109$.