Arun, Kamal and Vinay invested Rs. 8000, Rs. 4000 and Rs. 8000 respectively in a business. Arun left after six months. If after eight months, there was a gain of Rs. 4005, then what will be the share of Kamal?

$$\eqalign{ & {\text{Arun}}\,{\text{:}}\,{\text{Kamal}}\,{\text{:}}\,{\text{Vinay}} \cr & = \left( {8000 \times 6} \right):\left( {4000 \times 8} \right):\left( {8000 \times 8} \right) \cr & = 48:32:64 \cr & = 3:2:4 \cr & \therefore {\text{Kamal's}}\,{\text{share}} \cr & = Rs.\,\left( {4005 \times \frac{2}{9}} \right) \cr & = Rs.\,890 \cr} $$