Question

What will be the cost of making a closed cone of tin sheet having radius of base \[6m\] and slant height \[8m\] if the rate of making is \[Rs10/sq.m\] ?

Answer 1

Hint: It is said that we need to make a cone from a sheet of tin with the given dimensions. This hints to us that the area used to make this tin cone is to be found. When the value of surface area is found, we can multiply it with the value of the rate at which the making is done
Formulas used: The surface area of a cone is given by: \[A = \pi r\left( {r + h} \right)\]

Complete step-by-step answer:
The following data is given in the question,
The radius of the base of the cone is \[r = 6m\]
The slant height of the cone is \[h = 8m\]
The surface area of the cone is given by \[A = \pi r\left( {r + h} \right)\]
\[A = \pi 6\left( {6 + 8} \right) = 263.89\]
Now it is given that the rate per square meters is \[10\]
In order to get the total rate to make the tin cone, we multiply the surface area with the rate per meters squared
That is, \[264 \times 10 = 2640\]
We take the rounded off value because it is easier for calculation.
In conclusion, the cost of making a closed cone of tin sheet having radius of base \[6m\]and slant height \[8m\] is \[Rs.2640/ - \]
So, the correct answer is “ \[Rs.2640/ - \]”.

Note: The formula for finding the surface area of a closed cone needs to be used here. Some might use the formula where the area of the circular base is not included. That needs to be properly calculated and observed. The calculations must be done with at most caution. The units and measurements must be specified.