Q. 775.0( 1 Vote )

# Each question consists of two statements, namely, Assertion (A) and Reason (R). For selecting the correct answer, use the following code:Assertion (A): A hemisphere of radius 7 cm is to be painted outside on the surface. The total cost of painting at Rs 5 per cm2 is Rs 2300.Reason (R): The total surface area of a hemisphere is 3πr2.A. Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).B. Both Assertion (A) and Reason (R) are true but Reason (R) is not a correct explanation of Assertion (A).C. Assertion (A) is true and Reason (R) is false.D. Assertion (A) is false and Reason (R) is true.

Assertion is wrong and Reason is correct.

Explanation:

Assertion (A):

Given: A hemisphere of radius 7 cm.

Total surface area of the hemisphere is: 3πr2

Let S be the TSA of the hemisphere.

S = 3πr2 = 3π(7)2

S = 462cm2

The total cost to pain it: 462 × 5 = Rs 2310

Reason(R):

The total surface area of a hemisphere is 3πr2.

Assertion is wrong and Reason is correct.

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