Two soap bubbles of radii 4cm and 6 cm are in contact with each other. What is the radius of the common boundary?

Explanation

Here,`r=4cm, r_(2)=6 cm`
Radius of common boundary,
`r=(r_(1)r_(2))/(r_(1)-r_(2)) = (4 xx 6)/(6-4)`
`=12 cm`.