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The given questions is followed by three...

The given questions is followed by three statements. Study the statements carefully and decide which of the following statements (s) is //are necessary to answer the questions.
What is the total surface area of cone ?
(i) The area of the base of cone is 1386 `cm^(2)` ?
(ii) The curved surface area of the cone is 2310 `cm^(2)`.
(iii) The volume of the cone is 3696 `cm^(3)`.

A

I and either II or III

B

II and either I or III

C

III and either I or II

D

Any two of the three

Text Solution

AI Generated Solution

The correct Answer is:
To find the total surface area of a cone, we need to use the formula: \[ \text{Total Surface Area (TSA)} = \pi r (r + l) \] where: - \( r \) is the radius of the base of the cone, - \( l \) is the slant height of the cone. ### Step 1: Analyze the Statements 1. **Statement (i)**: The area of the base of the cone is \( 1386 \, cm^2 \). - The area of the base of the cone (which is a circle) is given by the formula: \[ \text{Area} = \pi r^2 \] - From this statement, we can find \( r \) using: \[ r^2 = \frac{1386}{\pi} \] 2. **Statement (ii)**: The curved surface area of the cone is \( 2310 \, cm^2 \). - The curved surface area (CSA) of the cone is given by: \[ \text{CSA} = \pi r l \] - This statement allows us to find \( l \) if we know \( r \). 3. **Statement (iii)**: The volume of the cone is \( 3696 \, cm^3 \). - The volume of the cone is given by: \[ V = \frac{1}{3} \pi r^2 h \] - This statement can help us find \( h \) if we know \( r \). ### Step 2: Determine Necessary Statements - To find the total surface area, we need both \( r \) and \( l \). - From **Statement (i)**, we can find \( r \). - From **Statement (ii)**, we can find \( l \) if we have \( r \). - **Statement (iii)** provides additional information but is not necessary to find \( l \) since we can find it using the first two statements. ### Conclusion - **Statement (i)** is necessary to find \( r \). - **Statement (ii)** is necessary to find \( l \). - **Statement (iii)** is not necessary to find the total surface area. Thus, the necessary statements to answer the question are **(i) and (ii)**. ### Final Answer: The correct option is that statements (i) and (ii) are necessary to answer the question about the total surface area of the cone. ---
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