Question

9. A tank is 20m in length, 15m in breadth and 4m
in depth. Find the cost of cementing its floor and
the four walls at the rate of 50 per square metre.
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Answer 1

Answer:

cost of cementing = ₹29,000

Step-by-step explanation:

here, TSA of cuboidal tank except top lead = 2(LB + BH + HL) - LB

                                             = 2(20 × 15 + 15 × 4 + 4 × 20) - 20 × 15

                                             = 2(300 + 60 + 80) - 300

                                             = 2(440) - 300

                                             = 880 - 300

                                             = 580 m²

now, cost of cementing = rate of cementing × TSA of cuboidal tank except top lead

                                       = ₹50/m² × 580m²

                                       = ₹29,000

∴ cost of cementing = ₹29,000.

hope it will help you.

Answer 2

length= 20m

breagth=15m

depth(height)=4m

since, Volume of tank = lbh

=20x15x4

=1400m^2

hence, the cost of floor walls=1400x50

=70000 rs