A, B and C enter into a partnership with their capital in the ratio \(\frac{2}{5}\;:\;\frac{3}{4}\;:\frac{5}{8}.\) After 4 months A increased his capital by 50%. B increased his capital by 25% and C decreased his capital by 20%. At the end of a year, there was a profit of Rs. 7800. What is the share of B in the profit?