A, B and C enter into partnership. A invests some money at the beginning, B invests double the amount after 6 months, and C invests thrice the amount after 8 months. If the annual gain be Rs.15000. A's share is? Options
A) 2999 B) 2778 C) 6000 D) 5000 E) 6612

Rationale: "x * 12 : 2 x * 6 : 3 x * 4 1 : 1 : 1 1 / 3 * 15000 = 5000 answer : d"
Answer: D