Assertion: The curved surface area of a cone is 550 cm² and its diameter is 14 cm. Then, its slant height is 25 cm.
Reason: The curved surface area of a cone having base radius r and slant height l is πrl.
(a) Both Assertion and Reason are true and Reason is a correct explanation of Assertion.
(b) Both Assertion and Reason are true and Reason is not a correct explanation of Assertion.
(c) Assertion is true and Reason is false.
(d) Assertion is false and Reason is true.

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Solution

(a) Both Assertion and Reason are true and Reason is a correct explanation of Assertion.

Reason (R) is clearly true.

$Curved surface area of the cone = π r l = \frac{22}{7} \times 7 \times 25 = 550 {cm}^{2}$
Reason (R) is clearly true.
Assertion (A) is true and reason(R) is a correct explanation of assertion (A) .

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Similar questions

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(a) Both Assertion and Reason are true and Reason is a correct explanation of Assertion. Reason (R) is clearly true. Curved surface area of the cone = πrl =227×7×25 =550 cm2 Reason (R) is clearly true. Assertion (A) is true and reason(R) is a correct explanation of assertion (A) .