Ninad, Vikas and Manav enter into a partnership. Ninad invests some amount at the beginning. Vikas invests double the amount after 6 months and Manav invests thrice the, amount invested by Ninad after 8 months. They earn a profit of Rs. 45000 at the end of the year. What is Manav's share in the profit? `R s .9000` b. `R s .12000` c. `R s .15000` d. `R s .2000` e. none of these