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 $Rs.$)

The average of $3$ numbers is $22$. If the first number is $\frac{3}{8}$ of the sum of the other two numbers,what is the first number?

The average of certain first consecutive natural numbers is $20.5$. Find their sum.

The average age of $8$ men is increased by $2$ years when $2$ of them,whose ages are $20$ years and $24$ years respectively,are replaced by $2$ women. What is the average age of these two women (in years)?

The average marks in English of a class of $24$ students is $56$. If the marks of three students were misread as $44, 45,$ and $61$ in lieu of the actual marks $48, 59,$ and $67$ respectively,then what would be the correct average?

The average age of Sachin $(S)$ and Ganguli $(G)$ is $35 \text{ years}$. If Kaif $(K)$ replaces Sachin,the average age becomes $32 \text{ years}$,and if Kaif $(K)$ replaces Ganguli $(G)$,the average age becomes $38 \text{ years}$. If the average age of Dhoni $(D)$ and Irfan $(I)$ is half of the average age of Sachin,Ganguli,and Kaif,then the average age of all the five people is: