O P Malhotra, S K Gupta and, Anubhuti Gangal Solutions for Chapter: Average, Exercise 1: Exercise

The average weekly salary of $15$ workers in a factory is $₹1285.$ If the salary of the manager is included, the average becomes $₹1355$. What is the manager's salary? Write the answer in $₹$.

The average distance travelled by a person in $4$ days is $250 \mathrm{km}.$ The distances travelled by him in first three days are $225 \mathrm{km}, 180 \mathrm{km}, 230 \mathrm{km},$ respectively. Find the distance travelled by him on the fourth day. Write the answer in $\mathrm{km}$.

In a class of $20$ girls and $15$ boys, the average weight of the class is $42 \mathrm{kg}.$ The average weight of the boys is $41.5 \mathrm{kg}.$ What is the average weight of the girls? Write the answer in $\mathrm{kg}$ in decimal.

The average of $10$ observations is $3.5.$ If two observations namely $3.5$ and $2.5$ are deleted, find the new average.

The average attendance of an office for the first four days of the week was $780$ and for the first five days it was $840$. How many were present on Friday?

The average number of eggs sold on Monday, Tuesday and Wednesday, in a shop was $43.$ The average for Tuesday, Wednesday and Thursday was $45.$ On Thursday the sale was $42.$ Find the sale on Monday.

Average of $10$ numbers is $30.$ Later on it was observed that the numbers $15, 23$ are wrongly written as $51$ and $32$ The correct average is

The average marks of $28$ students in Mathematics was $50.$ $8$ students left the school, then this average increased by $5$. What is the average of marks obtained by the students who left the school?