Question

find the cost of painting a cuboid of dimensions20cm*15cm*12cm at the rate of 5paisa per square centimeter

Answer 1

hello frnd!

here's ur answer...

we have to find it's TSA as it have been asked to find the cost of painting the cuboid.

given:-

→length of the cuboid=20cm

→breadth of the cuboid=15cm

→height of the cuboid=12cm

TSA of the cuboid=2(lb+bh+lh)

=2[(20×15)+(15×12)+(20×12)

=2(300+180+240

=2×720

=1440cm²

hence total cost of painting the cuboid if per m² costs 5 paisa=1440×5

=7200paisa

in rupees=7200/100

=₹72

hope this helps..!

Answer 2

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


If the cost of painting 1 m square = 5 paise
So, the cost of painting 1440cm square
= 1440 X 5
= 7200 paise = Rs. 72


...................OR................

5 paise = 5/100 (because 100paise = 1 rupee)
5paise = 0.05 rupees

1440 X 0.05
= Rs. 72