In a class of $100$ students, the mean marks obtained in a subject is $30$ and in another class of $50$ students the mean marks obtained in the same subject is $60 .$ The mean marks obtained by the students of two classes taken together is
$40$
$45$
$48$
$50$
The average salary per head of all the workers in a workshop is $Rs.\,850.$ If the average salary per head of $7$ technicians is $Rs.\, 1000$ and the average salary per head of the rest is $Rs.\, 780,$ find out the total number of workers in the workshop.
The average of $20$ numbers is $30$ and that of other $30$ numbers is $50 .$ What is the average of all the numbers.
Average of ten numbers is calculated. If each number was increased by $12 \%$, then the average
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 total attendance on three days were in the ratio $2: 5: 13$ respectively. The average charge per person for the entire three days is (in $Rs.$)
$12 \%$ of Kaushal's monthly salary is equal to $16 \%$ of Nandini's monthly salary. Suresh's monthly salary is half that of Nandini's monthly salary. If Suresh's annual salary is $Rs.\,1.08$ $lacs.$ What is Kaushal's monthly salary? (in $Rs.$)