Question

two circular cylinder of equal volume have their height in the ratio 1:2 ratio of their radii is

Answer 1

Let their heights be h and 2h and radii be r and R respectively then.

πr2h=πR2(2h)=>r2R2=2hh=21=>rR=2–√1=>r:R=2–√:1

Answer 2

since their volumes are equal
therefore ,
pie*r1^2*h1=pie*r2^2*h2
pie gets cancelled
r2^2/r1^2=h1/h2
putting value of heights in ratio
r2^2/r1^2=1/2
taking square roots
r2/r1=1/root 2
therefore 
r1/r2= root2/1
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