Question

Assertion (A)
The outer surface of a hemisphere of radius 7 cm is to be painted. The total cost of painting at Rs 5 per cm² is Rs 2300.

Reason (R)
The total surface area of a hemisphere is 3π r².

1. Both Assertion (A) and Reason (R) are true and Reason (R) is a correct explanation of Assertion (A).
2. Both Assertion (A) and Reason (R) are true but Reason (R) is not a correct explanation of Assertion (A).
3. Assertion (A) is true and Reason (R) is false.
4. Assertion (A) is false and Reason (R) is true.

Answer 1

Assertion (A) is false and Reason (R) is true.
Assertion (A):
Total surface area of the hemisphere =3πr³ 

`= (3xx22/7xx7xx7) "cm"^2`

= 462 cm²

Cost of painting at Rs 5 per cm² = Rs (462 × 5)

= Rs 2310

Hence, Assertion (A) is false.

Reason (R): The given statement is true.