Question

1. A plastic box 1.5 m long, 1.25 m wide and 65 cm deep is to be made. It is opened at the
top. Ignoring the thickness of the plastic sheet, determine:
(1) The area of the sheet required for making the box.
(ii) The cost of sheet for it, if a sheet measuring 1m² costs Rs 20.​

Answer 1

given length of box = 1.5

bredth of box= 1.25

depth of box=65cm 65\100 cm=0.65m

area of sheet required=area of cuboid- area of top which is open

area of sheet required=2(lb+bh+lh)-lb

=2(lb)+2(bh)+2(lh)- lb

= lb+2(bh)+2(lh)

=[1.5.*1.25+2*1.25*0.65+2*1.5*0.65]m^2

=[1.95+1.625+1.875]m^2

=5.45 m^2

area of sheet required=5.45m^2

cost of sheet pr 1 m^2 area=rs.20

cost of sheet of 5.45m^2 area=rs(5.45*20)

=rs 109