Q1. The average of n numbers is x. the first number is increased by 1, the second number is increased by 2, the third number is increased by 3 and so on. Find the average of new numbers.
Ans - 𝑥+𝑛+1/2
Q2. Ayush finds average of 20, 2 digits numbers. If the digits of one of the numbers is interchanged, average increases by 2.7. Find the difference between the digits of that 2 digits number.
Ans - 6
Q3. The average age of 40 students of a class is 15 years 3 months. Due to admission of 5 new students average becomes 15 years. If the age of the younger one is 10 years, find the average of remaining four students.
Ans - 13 years 9 months
Q4. In a T-20 match, required run rate to win is 8.4. If at the end of 16 over run rate is 6.5, find the run rate to win the match.
Ans - 16
Q5. Four boys and one girl go to a shopping mall for shopping. If each boy spends Rs.200 and the girl spends Rs.60 more than the average expenditure of all. Find the amount spent by the girl.
Ans - 260
Q6. The weight of 4 members out of 12 are measured in a sequence. Average weight is calculated after measuring weight of each member. Each time average is calculated and it is 1 kg more than previous average. Find the difference of weight of first and last membe
Ans - 6
Q7. The frequency distribution data is provided below if the average weight is 32, find the value of x.
Ans - 15
Q8. Average of 10 numbers is calculated as 21. Later it was found that one number was wrongly written as 26 instead of 16. Find the correct average.
Ans - 20
Q9. Aman was asked to find the average of n consecutive numbers starting from 1, but he added a number twice, then the wrong average calculated was 30 45.30 45. Find the number that was added twice.
Ans - 18
Q10. On Sunday the average number of visitors to a library is 330, and on other days the average number of visitors is 120. Find the average number of visitors in a month of 30 days beginning with Saturday.
Ans - 155
Q11. What will be average of 260 + 430 + 1610 + 410 ?
Ans - 429 + 429 + 419 + 49
Q12. Average of 6 numbers is 9. Average of the first two numbers is 10. If the average of the next three numbers is 8, find the last number.
Ans - 10
Q13. Out of 12 boys, the height of one-third of boys is 1 m 10cm, the height of remaining is 1 m 20 cm. Find the average height of all the boys.
Ans - 1 m 17 cm
Q14. After replacing an old student by a new student, who is three years old, it is found that the average age of a group of 10 students is the same as it was 6 months ago. Find the difference between the ages of replaced and new students
Ans - 5 years
Q15. Average of radii of two circles is 28 cm. What will be the sum of their perimeters?
Ans - 352
