Let investment of A = Rs. 7x Let investment of B = Rs. 9x Let investment of C is = Rs. 9x × (2/3) = 6x ∴ Weighted ratio of investment of A, B and C ⇒ 7x × 12 : 9x × 12 : 6x × 6 ⇒ 84x : 108x : 36x ⇒ 7 : 9 : 3 Let, Profit share of A = 7y Let, Profit share of B = 9y Let, Profit share of C = 3y ∴ Total profit = (7y +9y + 3y) = 19y ∴ Total profit = 8400 × (19y/7y) = Rs. 22800