Which is the greatest number?

$A, B$ and $C$ start a business by investing $Rs. 70000$ that earns them a profit of $Rs. 42000$ at the end of the year. $A$ invests his share in the profit in a scheme that gives $10\%$ interest compounded annually and $B$ invests his share in a scheme that gives $20\%$ interest compounded annually. $A$ gets $Rs. 2520$ as interest at the end of $2$ years and $B$ gets an interest of $Rs. 4200$ at the end of one year. Find $C$'s investment in the business.

$x \%$ of $y + y \%$ of $x = ?$

Five-ninths of a number is equal to $25$ per cent of the second number. The second number is equal to one-fourth of the third number. The value of the third number is $2960$. What is $30$ per cent of the first number?

$125 \%$ of $320 + x \%$ of $125 = 440$. Find the value of $x$.

In a mixture of milk and water,the proportion of water by weight was $75 \%$. If $15 \text{ gm}$ of water is added to $60 \text{ gm}$ of this mixture,what will be the new percentage of water by weight (in $\%$)?