Question

If four times the sum of the areas of the two circular faces of a cylinder of height 8 cm is equal to twice the curved surface area, then the diameter of the cylinder is (a) 4 cm (b) 8 cm (c) 2 cm (d) 6 cm

Answer 1

Answer:

Let radius of base be

′

r

′

m. Then

3(πr

2

+πr

2

)=2×2πrh

⇒6πr

2

=4πrh

⇒r=

6

4×6

=4m