B. 144
Feedback The ratio of their initial investment = 1/2 : 1/3 : 1/4
= 6 : 4: 3
Let's take the initial investment of P, Q and R as 6x, 4x and 3x respectively
A:B:C = (6x × 2 + 3x × 10) : 4x × 12 : 3x × 12
= (12 + 30) : 4 × 12 : 3 × 12
=(4 + 10) : 4 × 4 : 12
= 14 : 16 : 12
= 7 : 8 : 6
B's share = 378 × (8/21) = 18 × 8 = 144