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 income of $A$ for $15$ days is $Rs. 70$. The average for the first five days is $Rs. 60$ and that for the last nine days is $Rs. 80$. $A$'s income for the sixth day is (in $Rs.$):

The average weight of three boys $A, B$ and $C$ is $54 \frac{1}{3} \, kg,$ while the average weight of three boys $B, D$ and $E$ is $53 \, kg.$ What is the average weight of $A, B, C, D$ and $E$ (in $kg$)?

$10$ years ago,the average age of a family of $4$ members was $24$ years. Two children have been born (with an age difference of $2$ years),and the present average age of the family remains the same. The present age of the youngest child is (in years):

The mean of the marks obtained by $100$ students is $60$. If the marks obtained by one of the students was incorrectly calculated as $75$ whereas the actual marks obtained by him were $65$,what is the correct mean of the marks obtained by the students?

The batting average for $40$ innings of a cricket player is $50$ runs. His highest score exceeds his lowest score by $172$ runs. If these two innings are excluded,the average of the remaining $38$ innings is $48$ runs. The highest score of the player is