If $U: V = 6: 7$ and $V: W = 21: 6$,then find $U: V: W$.

At present,Kavita is twice Sarita's age. $8 \ yr$ hence,the respective ratio between Kavita's and Sarita's ages will be $22:13$. What is Kavita's present age (in $yr$)?

$A, B, C$ and $D$ purchase a gift worth $Rs. 60$. $A$ pays $\frac{1}{2}$ of what others are paying,$B$ pays $\frac{1}{3}$ of what others are paying,and $C$ pays $\frac{1}{4}$ of what others are paying. What is the amount paid by $D$?

The railway fares of air-conditioned sleeper class and ordinary sleeper class are in the ratio $4:1$. The number of passengers who travelled by air-conditioned sleeper and ordinary sleeper classes were in the ratio $3:25$. If the total collection was ₹ $37,000$,how much did air-conditioned sleeper passengers pay (in ₹) (in $,000$)?

In a college,$150$ students of $MBA$ are enrolled. The ratio of boys to girls is $7:8$. There are three disciplines in the college: Marketing,$HR$,and Finance. In the Marketing discipline,there are $50\%$ of the total girls and $40\%$ of the total boys. In the $HR$ discipline,there are $30\%$ of the total girls and $30\%$ of the total boys. In the Finance discipline,there are $20\%$ of the total girls and $30\%$ of the total boys. $7$ 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 enrolled in all three disciplines. What is the ratio of boys to girls only in the Marketing discipline?

$A$ and $B$ together have ₹ $6300$. If $\frac{5}{19}$ of $A$'s amount is equal to $\frac{2}{5}$ of $B$'s amount,then the amount of $B$ is (in ₹):