A, B and C enter into a partnership in the ratio $$\frac{7}{2}$$ : $$\frac{4}{3}$$ : $$\frac{6}{5}$$ . After 4 months, A increases his share 50%. If the total profit at the end of one year be Rs. 21,600, then B's share in the profit is:

Explanation:-

$$\eqalign{ & {\text{Ratio}}\,{\text{of}}\,{\text{initial}}\,{\text{investments}} \cr & = \left( {\frac{7}{2}:\frac{4}{3}:\frac{6}{5}} \right) = 105:40:36 \cr & {\text{Let}}\,{\text{the}}\,{\text{initial}}\,{\text{investments}}\,{\text{be}} \cr & 105x,\,40x\,{\text{and}}\,36x \cr & \left( {105x \times 4 + \frac{{150}}{{100}} \times 105x \times 8} \right):\left( {40x \times 12} \right):\left( {36x \times 12} \right) \cr & = 1680x:480x:432x = 35:10:9 \cr & {\text{Hence,}}\,{\text{B's}}\,{\text{share}} \cr & = Rs.\,\left( {21600 \times \frac{{10}}{{54}}} \right) \cr & = Rs.\,4000 \cr}$$