If $m : n = 3 : 2,$ then $(4m + 5n) : (4m - 5n)$ is equal to:

In a mixture of petrol and kerosene,the quantity of petrol is $99 \text{ litres}$. If this same quantity of petrol were present in another mixture of petrol and kerosene where the total volume is $198 \text{ litres}$ less than the actual mixture,the concentration of petrol in the actual mixture would be $13.33 \%$ less than that of the new mixture. What is the concentration (in $\%$) of petrol in the actual mixture?

The population of a town is $3,11,250$. The ratio between women and men is $43:40$. If there are $24\%$ literate among men and $8\%$ literate among women,the total number of literate persons in the town is:

In a college, $150$ students of $MBA$ are enrolled. The ratio of boys to girls is $7:8$. There are three disciplines: Marketing, $HR$, and Finance. In Marketing, $50\%$ of the girls and $40\%$ of the boys are enrolled. In $HR$, $30\%$ of the girls and $30\%$ of the boys are enrolled. In Finance, $20\%$ of the girls and $30\%$ of the boys are enrolled. $7$ boys and $9$ girls are in both $HR$ and Marketing. $6$ boys and $7$ girls are in both $HR$ and Finance. $5$ boys and $8$ girls are in both Marketing and Finance. $2$ boys and $3$ girls are in all three disciplines. Find the ratio of the number of boys in both Marketing and Finance to the number of girls only in Finance.

Salaries of Ravi and Sumit are in the ratio $2:3$. If the salary of each is increased by $₹4000$,the new ratio becomes $40:57$. What is Sumit's present salary (in $₹$)?

If $40 \%$ of a number is equal to two-thirds of another number,what is the ratio of the first number to the second number?