Question

32) A cubical box has each edge 13cm and another cuboidal box 20 cm long, 15.5 cm wide and 10 cm
high.
(a) Which box has the greater lateral surface area and by how much?
(b) Which box has the smallest total surface area and by how much?​

Answer 1

Answer:

Lateral surface area of cube = 4edge

2

=4(10)

2

=400

lateral surface area of cuboid =2h(l+b)

2×8(12.5+10)

=16×22.5

=360

So, the lateral surface area of the cube is larger by (400−360=40)cm

2

(ii) Total surface area of cube = 6edge

2

=6(10)

2

=600

lateral surface area of cuboid =2(lb+bh+hl)

2(12.5×10+10×8+8×12.5)

=2(125+80+100)

=610

So, the total surface area of cuboid is larger by (610−600=10) cm

2