Question

A wooden cone has radius 30m,height 40cm and slant height 50cm.Calculate the cost to paint the face of ten cones at a rate of 50rs per square metre​

Answer 1

Given:-

• Radius of wooden cone = 30 m
• Height of the cone = 40 cm
• Slant height of the cone = 50 cm

To find:-

• The cost to paint the face of 10 cones at the rate of Rs.50 per square metre.

Solution:-

Here we are given with the dimensions of the cone. As it is said to find the cost of painting face of the cost, it means we need to find the Curved surface area of the cone.

Dimensions of the cone are as follows:-

• Radius = 30 m
• Slant height = 50 cm

Here we need to convert the unit of slant height into m.

We know,

1 m = 1/100 cm

Hence,

• Slant height = 50/100 = 0.5 cm

We know,

✭ Curved Surface Area of the cone = πrl sq.units

Hence,

CSA of the wooden cone = 22/7 × 30 × 0.5

=> CSA of the cone = 330/7 = 47.14 cm²

Now,

It is given that,

Cost of painting 1 m² = Rs.50

Cost of painting 47.14 = 47.14 × 50 = Rs.2357

Therefore cost of painting one cone is Rs.2357.

Now,

Cost of painting one cone is Rs.2357

Cost of painting 10 cones = 2357 × 10 = Rs.23570

Hence the cost of painting the face of 10 wooden cone will be Rs.23570.

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