The average temperature of Monday,Tuesday,Wednesday and Thursday is $60^{\circ}$. The average temperature for Tuesday,Wednesday,Thursday and Friday is $63^{\circ}$. If the ratio of temperature for Monday and Friday is $21: 25,$ then what is the temperature of Friday? (in $^{\circ}$)

The average age of students of a class is $15.8 \text{ years}$. The average age of boys in the class is $16.4 \text{ years}$ and that of the girls is $15.4 \text{ years}$. The ratio of the number of boys to the number of girls in the class is:

The average expenditure of a man for the first five months is $Rs. 120$ and for the next seven months is $Rs. 130$. His monthly average income in $Rs.$ if he saves $Rs. 290$ in that year,is

The average weight of $8$ sailors in a boat is increased by $1 \, kg$ if one of them weighing $56 \, kg$ is replaced by a new sailor. The weight of the new sailor is (in $kg$):

In a class,the average height of $35$ girls was measured as $160 \,cm$. Later,it was discovered that the height of one of the girls was misread as $144 \,cm$,while her actual height was $104 \,cm$. What was the actual average height of the girls in the class? (in $cm$) (rounded off to two digits after decimal)

The average of $30$ numbers is $15$. The average of the first $18$ numbers is $10$ and that of the next $11$ numbers is $20$. The last number is: