Question

7. The height of a cylinder is doubled and
radius is tripled then its curved sur-
face area will become ..... times. [ ]
A) 7
B) 6 C) 9
D) 12
​

Answer 1

Answer:

(B) 6 times

Step-by-step explanation:

Curved surface area of cylinder of height h and radius r is given by 2πrh.

When height = 2h (that is double)

and radius = 3r (that is triple)

the curved surface area will become

2π(3r)(2h)

= (2*3*2) (πrh)

= 12 πrh

= 6 (2πrh) which is 6 times the old one. (Plz mark it as brainliest if it helps)