Jhon, Mona and Gordon, three US based business partners, jointly invested in a business project to supply nuclear fuel to India. As per their share in the investment, Gordon will receive $$\frac{2}{3}$$ of the profits whereas Jhon and Mona divided the remainder equally. It is estimated that the income of Jhon will increase by $ 60 million when the rate of profit rises from 4% to 7%. What is Mona's capital ?

Fraction of profit received by each one of Jhon and Mona
$$\eqalign{ & = \frac{{\left( {1 - \frac{2}{3}} \right)}}{2} \cr & = \frac{1}{6} \cr} $$
Ratio of capitals of Jhon, Mona and Gordon = Ratio of their profits
$$\eqalign{ & \frac{1}{6}:\frac{1}{6}:\frac{2}{3} = 1:1:4 \cr & {\text{Let the total capital be Rs}}{\text{.}}x \cr & {\text{Then,}} \cr & \frac{1}{6}{\text{of }}\left( {7\% {\text{ of }}x - 4\% {\text{ of }}x} \right) \cr & = \$ {\text{ 60 million}} \cr & \Rightarrow 3\% \,{\text{of }}x = \$ {\text{ }}3{\text{60 million}} \cr & \Rightarrow x = \$ \left( {\frac{{360 \times 100}}{3}} \right){\text{million}} \cr & \Rightarrow x = \$ {\text{ 12000 million }} \cr & \therefore {\text{ Mona's capital }} \cr & {\text{ = }}\left( {\frac{1}{6} \times \$ {\text{12000 million }}} \right) \cr & = \$ \,200{\text{0 million }} \cr} $$