If `N_(1), N_(2), N_(3)`���Are the number of molecules with molecular masses `M_(1), M_(2), M_(3)`
Channel: Doubtnut
Date: 19/01/2020

If `N_(1), N_(2), N_(3)`���Are the number of molecules with molecular masses `M_(1), M_(2), M_(3)`��.respectively, then average molecular mass is expressed as