Question

The ratio of the total surface area to the lateral surface area of a cylinder with base radius 80 cm and height 20 cm is

(a) 2 : 1 (b) 3 : 1 (c) 4 : 1 (d) 5 : 1

Answer 1

Given

r=80cm, h=20cm

TSA=2πr(h+r)

TSA=2π(80)(20+80)

TSA=2π(80)(100)............ (1)

LSA=2πrh

LSA=2π(80)(20)..........(2)

eq. (1)/eq.(2)

We get

==5

so,

TSA:LSA=5:1