Question

Length breadth and height of a rectangular tank is 25m 20 m and 10 respectively . Find the cost of painting its outer surface at ₹ 3per square metre

Answer 1

Answer:

Rs 4200

Step-by-step explanation:

Find the surface area (without the top):

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

Surface area = (25 x 20) + 2(20 x 10) + 2(25 x 10) = 1400 m²

Find the cost:

1 m² = Rs 3

1400 m² = 3 x 1400 = Rs 4200

Answer: It costs Rs 4200

Answer 2

Area of the 1 outer surface is 10x25=250squaremetere

as two side is equal of rectangle then, the 2 outer surface are will 2×250=500squaremetere

and other 2 will
(20×2)squaremetere×2
=80squaremetere

then the total area (500+80)=580squaremetere


cost 3×580=1740Rs.