Question

please give me solutions​

Answer 1

Answer:

Curved surface area of cone will be painted=πrl

h=1m;radius= 40/2= 20cm=0.2m

and let l be the slant height,

l² = h²+r²= 1²+ 0.2²

⇒l= √1+0.04= √1.04= 1.02 (∵ √1.04 =1.02 is given in the question)

⇒Curved surface area of 1 cone=πrl=(3.14×0.2×1.02)m² =0.64046m²

⇒ Curved surface area of 50 cones=50×0.64046=32.028m²

Cost of painting 1m² =Rs.12

∴ Cost of painting 32.028m² =(12×32.028)=384.336m² ≈384.34

∴ Cost of painting 50 cones is Rs.384.84

Answer 2

Step-by-step explanation:

given,

r=20cm.

h=100cm.

l=√h^2+r^2

=√100^2+20^2

=√10,000+400

=√10400

=√1.04

=1.02

CSA of each cone=πrl

=3.14×20×1.02

=64.056 cm.^2

CSA of 50 such cone=64.056×50

=3202.8 cm.^2

again,

cost of painting 1m^2 area=rs.12

cost of painting 3202.8 m^2 area=12×3202.8

=38433.6 rs