An employer reduces the number of his employees in the ratio $9:7$ and increases their wages in the ratio $14:15$. Find the ratio in which the total bill of wages increases or decreases.

The sum of two numbers is three times their difference. What is the ratio of the two numbers?

$A$ sum of ₹ $15525$ is divided among Sunil,Anil and Jamil such that if ₹ $22$,₹ $35$ and ₹ $48$ be diminished from their shares respectively,their remaining sums shall be in the ratio $7: 10: 13$. What would have been the ratio of their sums if ₹ $16$,₹ $77$ and ₹ $37$ respectively were added to their original shares?

When $x$ is added to each term of $7: 13$,the ratio becomes $2: 3$. The value of $x$ is

$A$ person's present age is two-fifth of the age of his mother. After $8$ years,he will be one-half of the age of his mother. How old is the mother at present (in $years$)?

If $a: b = 3: 5$ and $b: c = 4: 7,$ then $a: c$ is equal to