#7668. The average age of all employees of M/s XYZ is 35 years. It was later found that age of one of the employees has been taken as 10 years less than his actual age, so the new average after correction increased by 0.5 years. Find the number of employees of M/s XYZ.

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#7667. The average of the age of A, B, and C is 25 years, while the average of the age of A, B, and D is 28 years. If D is 28 years old, then what is the age of C?

]]>#7666. The average weight of 3 group of friends of 50, 30, and 20 members respectively are 50 kilograms, 52 kilograms, and 55 kilograms. What is the average weight of all the friends taken together?

]]>#7665. Find the average of cubes of natural numbers up to 12.

]]>#7664. Find the average of squares of natural numbers up to 6.

]]>#7663. The average of coins with a group of friends reduces by 1, when one friend having 20 coins leaves the group. Find the number of friends left in the group given that originally, average of coins was 15.

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Neat work!

#7662. The average age of 8 persons is increased by 2 years when one of them, whose age is 24 years is replaced by a new person. Find the age of the new person.

]]>#7661. The average salary of A, B, and C is $35000 per annum. Also, the average salary of D and E is $38000 per annum. What is the average salary per annum of all the five taken together?

]]>#7660. The average age of a man and his son is 35 years. The ratio of their ages is 5 : 2 respectively. What is the son's age?

]]>#7559. Out of seven given numbers, the average of the first four numbers is 4 and that of the last four numbers is also 4. If the average of all the seven numbers is 3, find the fourth number.

]]>#7558. The salary of five members of a family is $10,000, $12,000, $17,000, $15,000, and $14,000. Find the average salary of all the members of the family using assumed mean.

]]>#7557. The average number of toffees with 6 friends is 10. If each of them eats one toffee, then find the average number of toffees with them, now.

]]>#7556. In a class, there are 40 boys and their average age is 16 years. One boy, aged 17 years, leaving the class and another joining, the average age becomes 15.875 years. Find the age of the new boy.

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