Assertion (A)
The curved surface area of a cone of base radius 3 cm and height 4 cm is 15π cm2.
Reason (R)
Volume of a cone $=\pi r^{2} h$
(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.
(c) Assertion (A) is true and Reason (R) is false.
Assertion (A):
Curved surface area of a cone $=\pi r \sqrt{r^{2}+h^{2}}$
$=\pi \times 3 \times \sqrt{(3)^{2}+(4)^{2}}$
$=\pi \times 3 \times \sqrt{9+16}$
$=\pi \times 3 \times \sqrt{25}$
$=15 \pi \mathrm{cm}^{2}$
Hence, Assertion (A) is true.
Reason (R): The given statement is false.