Multiply the given ratio one-half to one-third to one-fourth by the lowest common multiple of 2, 3 and 4, which is 12, to get an initial investment ratio of 6 to 4 to 3. After two months, A withdraws half his capital, making his effective capital 6 units for 2 months plus 3 units for 10 months, equaling 42 unit-months. B and C keep their capital for the full year, yielding 48 unit-months for B and 36 unit-months for C, so the new ratio is 42 to 48 to 36, which simplifies to 7 to 8 to 6. Since the total of 21 parts represents 378, one part is 18, and B's share of 8 parts is 144.