21 If two liquids of same masses but densities

ρ₁ and ρ₂ respectively are mixed, then density of mixture is given by

(a)  ρ=(ρ₁ + ρ_2)/2                                     (b)   ρ=(ρ₁ + ρ_{2)/( 2 ρ1 ρ2)}

(c)   ρ=_{( 2 ρ1 ρ2) /}  (ρ₁ + ρ₂₎                   (d)  ρ=_{(  ρ1 ρ2) /}  (ρ₁ + ρ₂₎

Answer-c