The average marks of a student obtained in Physics,Chemistry,and Biology is $70.$ If the student obtained $90$ marks in Mathematics,then the new average is

$A$ man covers $\frac{1}{3}$ of his journey by train at $80\, km/h$,the next $\frac{1}{3}$ by bus at $60\, km/h$,and the rest by bicycle at $30\, km/h$. Find the average speed of the man during the whole journey (in $km/h$).

The sum of five consecutive integers is $a$ and the sum of the next five consecutive integers is $b$. Then $\frac{(b-a)}{100}$ is equal to

$A$ student bought $4$ books for $Rs. 120$ from one book shop and $6$ books for $Rs. 150$ from another. The average price (in rupees),he paid per book was

Visitors to a show were charged $Rs. 15$ each on the first day,$Rs. 7.50$ on the second day,$Rs. 2.50$ on the third day,and the total attendance on the three days was in the ratio $2:5:13$ respectively. The average charge per person for the entire three days is (in $Rs.$):

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 $kg$).