$A$ man spends $Rs. 1800$ monthly on an average for the first four months and $Rs. 2000$ monthly for the next eight months and saves $Rs. 5600$ a year. His average monthly income is (in $Rs.$)

The average of $30$ numbers is $12$. The average of the first $20$ of them is $11$ and that of the next $9$ is $10$. The last number is:

The average price per $kg$ of rice at $10$ different places was $Rs. 4.85$. After a week,the price per $kg$ was increased by $20$ paise at $3$ places and decreased by $10$ paise at $1$ place. What is the new average price per $kg$ in $Rs.$?

The sum of eight consecutive numbers of Set $A$ is $376$. What is the sum of $5$ consecutive numbers of another set if its minimum number is $15$ ahead of the average of Set $A$?

The average salary of workers in $AMS$ careers is $Rs. 2,000$,the average salary of faculty is $Rs. 4,000$,and the average salary of management trainees is $Rs. 1,250$. The total number of workers could be:

The average earning of a mechanic for the first four days of a week is $Rs. 18$ and for the last four days is $Rs. 22$. If he earns $Rs. 20$ on the fourth day,his average earning for the whole week is (in $Rs.$)