The mean weight of $34$ students of a school is $42 \, kg$. If the weight of the teacher is included,the mean weight increases by $400 \, g$. Find the weight of the teacher (in $kg$).

$A$ man travels by a car to his office at $60 \, km/h$ and returns home along the same route at $20 \, km/h$. Find the average speed of his whole journey (in $km/h$).

In the first $10$ overs of a cricket game,the run rate was only $3.2$. What should be the run rate in the remaining $40$ overs to reach the target of $282$ runs?

The average of $3$ consecutive numbers is $n$. If the next two consecutive numbers are also included,the average of the five numbers will

In an examination,the average marks obtained by the girls of a class is $85$ and the average marks obtained by the boys of the same class is $87$. If the girls and boys are in the ratio $4:5$,the average marks of the whole class (approx.) is closest to:

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: