Question

please solve
the ratio of csa to the tsa of right circular cylinder is 1:2 find the volume of cylinder if its tsa is 616cm^2.?

Answer 1

CSA/TSA=1/2
or 2πrh/2πr(h+r)
or h+r=2h
or h=r
Again 2πrh/2πr(h+r)=1/2
or 2πrh/616=1/2
or 4πrh=616
or rh=49
or r=√49(since r=h)
or r=7 cm
Now Volume of cylinder=πr^2h
=22/7*7*7*7 cm^3
=1078cm^3

Answer 2

CSA/TSA =1/2

2πrh/616=1/2

2πrh=616/2

πrh=308/2=154

now again
TSA of cylinder= 616

2πr(h+r). =616

2πrh+2πr^2=616

2*154+2πr^2=616

2×22/7r^2. =616-308 =308

r^2. =308*7/44

r^2. =7*7

r^2=. 7^2

r=7

now

Vol of cylinder. =πr^2h. = πrh×r =154×7 =1078cubicm