Question

if 2 cylinder of equal volume have heights in the ratio 1:9 the radius have to be find.

Answer 1

we know that
volume of a cylinder = πr²h 

here 
let 1st cylinder having radius = x
and 2nd having radius = y 

also given that 
heights of cylinders are in the ratio of 1:9 

=> 1st cylinder having height = 1h
and 2nd = 9h

now 

both cylinders having equal volumes
=> πx²h = πy²×9h
=> x² = 9y² = (3y)²
=> x= 3y

hence 
radii of cylinders are in ratio of 1:3 answer

⭐✡ hope it helps ⭐✡