Q.1
The average age of 30 students is 9 years. If the age of their teacher is included, the average age becomes 10 years. The age of the teacher (in years) is :
Q.2
The average of 6 observations is 45.5. If one new observation is added to the previous observations, then the new average becomes 47. The new observation is :
Q.3
The average age of P, Q and R is 15 years more than R's age. If the total age of P and Q together is 39 years, then R's age is ?
Q.4
Find the average of 1.11, 0.01, 0.101, 0.001, 0.11 = ?
Q.5
The average pocket money of 3 friend A, B, C is Rs. 80 in a particular month. If B spends double and C spends triple of what A spends during that month and if the average of their unspent pocket money is Rs. 60, then A spends (in Rs.)-
Q.6
The average age of group of 20 girls is 15 years and that of another group of 25 boys it is 24 years. The average age of the two groups mixed together is :
Q.7
The average of nine number is 50. The average of first five numbers is 54 and that of the last three numbers is 52. Then the sixth number is :
Q.8
From a class of 42 boys, a boy aged 10 years goes away and in his place, a new boy is admitted. If on account of this change, the average age of the boys in that class increases by 2 months, the age of the newcomer is :
Q.9
If the mean of 4 observations is 20, when a constant 'c' is added to each observation, the mean becomes 22. The value of c is :
Q.10
The average of 9 observations was found to be 35. Later on, it was detected that an observation 81 was misread as 18. The correct average of the observation is -
Q.11
Out of 20 boys, 6 are each of 1 m 15 cm height, 8 are of 1 m 10 cm and rest of 1 m 12 cm. The average height of all of them is :
Q.12
The average of the largest and smallest 3 digits numbers formed by 0, 2 and 4 would be :
Q.13
If the arithmetic mean of 7, 5, 13, x and 9 is 10, then the value of x is :
Q.14
3 years age, the average age of a family of 5 members was 17 years. A baby having been born, the average age of the family is same today. The present age of the baby is :
Q.15
The average of five numbers is 7. If three new numbers would be added, then the new average comes out to be 8.5. What is the average of those three new numbers ?
Q.16
The average age of a family with 5 members is 28. If one of the 5 members of age 20 is excluded the average age of the family becomes -
Q.17
If the average of 5 consecutive integers is x then, find the average of next to next 5 consecutive integers.
Q.18
The average age of 20 boys in a class is 12 years. 5 new boys are admitted to the class whose average age is 7 years. The average age of all the boys in the class becomes:
Q.19
The frequency distribution data is given below. If the average age is 17 years, the value of m is
Age (in years) : 8 20 26 29
No. of people : 3 2 m 1
Q.20
The average of six numbers is 3.95. The average of two of them is 3.4, while the average of the other two is 3.85. The average of the remaining two numbers is :
Q.21
The average (arithmetic mean) of 330, 360 and 390 is :
Q.22
A set A consists of integers 27, 28, 30 and 33. If integer k is included in the set, the average of set A will increase by 30%. What is the value of integer k ?
Q.23
The average age of 40 students of class is 18 years. When 20 new students are admitted to the same class, the average age of the students of the class is increased by 6 months. The average age of newly admitted students is ?
Q.24
The mean weight of 34 students of a school is 42 kg. If the weight of the teacher be included, the mean rises by 400 grams. Find the weight of the teacher (in kg.)
Q.25
Five years ago, the average age of P and Q was 25. The average age of P, Q and R today is 25. Age of R after 5 years will be :
Q.26
The average age of husband, wife and their child 3 years ago was 27 years and that of wife and the child 5 years ago was 20 years. The present age of the husband is :
Q.27
The average of 10 items was found to be 80 but while calculating, one of the items was counted as 60 instead of 50. Then the correct average would have been :
Q.28
The average age of 24 boys and their teacher is 15 years. When the teacher's age is excluded, the average age decreases by 1 year. The age of the teacher is :
Q.29
The average age of four boys A, B, C and D is 5 years and the average age A, B, D, E is 6 years. C is 8 years old. The age of E is (in years) :
Q.30
A librarian purchased 50 storybooks for his library. But he saw that he could get 14 books more by spending Rs. 76 more but per book average becomes Rs. 1 less. The average price (in Rs.) of each book he bought, was :
0 h : 0 m : 1 s