When wrapping paper is used at least, two schoolbags should be folded together.

If the foundation height is 25x 15, it becomes 4x2=8cm.

The volume is 25x 15x8=3000 cubic centimeters.

The surface area is (25x15+15x8+25x8) x2.

=(375+ 120+200)x2

=695x2

= 1390 cm2