Question

A swimming pool is 20m in length,15m in breadth,and 4m in dept. Find the cost of cementing its floor and walls at the rate of ₹12 per square metere.

Answer 1

Lateral surface area of pool including floor= lb+2h(b+l)
=20×15+2×4(15+20)
=300+8(35)
=300+280
=580m^2
Cost of cementing=580m^2×12
=6960rupees

Answer 2

solution:
 
 cost of cementing the swimming pool=[lateral surface area(LSA) of the cuboidal(cuboid shaped)swimming pool+ area of floor(area of bottom)]x cost of cementing per metre.square.

                  cost of cementing (in₹) =[2h(l+b)+lb] x 12
                                                           =[2(4)(20+15)+(20)(15)]x12
                                                           =[8(35)+300]x12
                                                           =[280+300]x12
                                                           =[580]x12
                           cost of cementing  =₹6960