Question

solid cylinder has total surface area of 48 pi
$\pi$
cm^2 . Its total surface area is 8/5 times of its curved surface area. Find the radius of the cylinder.​

Answer 1

Answer:

Step-by-step explanation: Let r and h be the radius and height of the cylinder.

∴ Total surface area =48πcm2

 

2πrh+2πr2 =48π

2π(rh+r 2 )=48π

⇒rh+r2=2π/48π​

 

⇒rh+r2 =24 …………(i)

and curved surface area =8/5  otal surface area

⇒2πrh= 8/5 .48π

⇒2πrh=30π

⇒rh= 2π/30π​  

⇒rh=15 …………….(ii)

From (i),

15+r2=24

⇒r2 =24−15

⇒r2 =9

⇒r=3cm