The average weight of a class of $24$ students is $35 \, kg$. If the weight of the teacher is included, the average weight increases by $400 \, g$. The weight of the teacher is (in $kg$):

$A$ batsman,in his $12^{th}$ innings,makes a score of $63$ runs and thereby increases his average score by $2.$ The average of his score after $12^{th}$ innings is

The average of runs scored by a cricketer in his $99$ innings is $99$. How many runs will he have to score in his $100^{\text{th}}$ innings so that his average of runs in $100$ innings may be $100$?

The average marks of students in an examination was $65$. It was later found that the marks of one student had been wrongly entered as $83$ instead of $38$. If there were $50$ students, what is the correct average?

The average score of Rahul,Manish,and Suresh is $63$. Rahul's score is $15$ less than Ajay and $10$ more than Manish. If Ajay scored $30$ marks more than the average score of Rahul,Manish,and Suresh,what is the sum of Manish's and Suresh's scores?

Average rainfall on Monday,Tuesday,Wednesday and Thursday is $420.5\, cm$ and average on Tuesday,Wednesday,Thursday and Friday is $440.5\, cm$. If the ratio of rainfall for Monday and Friday is $20:21$,find the rainfall in $cm$ on Monday and Friday.