A and B started a business in partnership investing Rs. 20,000 and Rs. 15,000 respectively. After six months, C joined them with Rs. 20,000. What will be B's share in total profit of Rs. 25,000 earned at the end of 2 years from the starting of the business?

$$\eqalign{ & A:B:C \cr & = \left( {20000 \times 24} \right):\left( {15000 \times 24} \right):\left( {20000 \times 18} \right) \cr & = 4:3:3 \cr & \therefore {\text{B's}}\,{\text{share}} = Rs.\,\left( {25000 \times \frac{3}{{10}}} \right) \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = Rs.\,7500 \cr} $$