Question

Ques 2- Edge of a Cubical box is 20 cm. What is cost
of paint an box an seate Rs 10/m²
​

Answer 1

Step-by-step explanation:

(i)Cube:

Total surface area = 6l

2

=6×10

2

= 6×100=600m

2

Cuboid:

Total surface area = 2(lb + bh + lh)

= 2[(12.5×10)+(10×8)+(8×12.5)]

= 2[125+80+100]

= 610m

2

If each edge of the cube is doubled, then,

l = 20

b =25

h =16

Then, Cube's Total surface area = 6l

2

= 6 x 20

2

= 6 x 400

= 2400m

2

Cuboid:-Total surface area when each side is doubled = 2(lb+bh+lh)

= 2[(25 x 20) + (20 x 16) + (16 x 25)]

= 2[500+320+400]= 2[1220]

= 2440m

2

Thus, If each edge of the cube and cuboid is doubled, then its T.S.A will increase 4 times.