Let probability of sale of brand 1 is P(A). Similarly, for brand 2 is P(B) and brand 3 is P(C) Given, P (A) = 10050​ = 21​ P (B) = 10030​ = 103​ P (C) = 10020​ = 51​ and also tet the probability of required warranty work of brand (1) is P (A) Similarly, for brand 2 is P(B) and for brand 3 is P(C). ∴ P (A) = 10025​ = 41​ P (B) = 10020​ = 51​ P (C) = 10010​ = 101​ Now, required probability = 21​×14+103​×51​+51​×101​ = 81​+503​+501​ = 40050+24+8​ = 40082​ = 0.205