1.
The average age of a jury of 5 is 40. If a member aged 35 resigns and a man aged 25 becomes a member, then the average age of the new jury
2.
The average of the runs made by Raju, Shyam, and Hari is 7 less than that made by Shyam, Hari, and Kishore. If the number of Kishore's run is 35, what is Raju's run?
3.
The mean of 50 numbers is 30. Later it was discovered that two entries were wrongly entered as 82 and 13 instead of 28 and 31. Find the correct mean.
4.
One-third of a certain journey is covered at the rate of 25 km/h, one-fourth at the rate of 30 km/h, and the rest at 50 km/h. The average speed for the whole journey is:
5.
The average of 5 numbers is 140. If one number is excluded, the average of the remaining 4 numbers is 130. The excluded number is
6.
The average weight of 5 persons sitting in a boat is 38 kg. The average weight of the boat and the persons sitting in the boat is 52 kg. What is the weight of the boat?
7.
There are 50 students in a class. Their average weight is 45 kg. When one student leaves the class the average weight reduces by 100 g. What is the weight of the student who left the class?
8.
Out of 4 numbers, whose average is 60, the first one is one-fourth of the sum of the last three. The first number is:
9.
In a class, the average score of girls in an examination is 73 and that of boys is 71. The average score for the whole class is 71.8. Find the percentage of girls.
10.
The average of the first 100 positive integers is:
11.
Out of the three numbers, the first number is twice the second and the second is thrice of the third number. If the average of these 3 numbers is 20, then the sum of the largest and smallest numbers is:
12.
The average age of 40 students in a class is 18 yr. When 20 new students are admitted to the same class, the average age of the students in the class is increased by 6 months. The average age of newly admitted students is
13.
The average age of 40 students in a class is 15 yr. When 10 new students are admitted, the average age is increased by 0.2 yr. The average age of new students is
14.
The average of 6 observations is 45.5. If one new observation is added to the previous observation, then the new average becomes 47. The new observation is
15.
The average of marks scored by the students of a class is 68. The average of marks of the girls in the class is 80 and that of boys is 60. What is the percentage of boys in the class?
16.
The average age of 30 boys in a class is 15 yr. One boy aged 20 yr, left the class but two new boys came to his place whose ages differ by 5 yr. If the average age of all the boys now in the class still remains 15 yr, the age of the younger newcomer is
17.
Out of 10 teachers of a school, one teacher retires and in his place, a new teacher of age 25 yr joins. As a result of it, the average age of the teachers is reduced by 3 yr. The age of the retired teacher is
18.
3 yr ago, the average age of a family of 5 members was 17 yr. A baby having been born, the average age of the family is the same today. The present age of the baby is
19.
The mean weight of 34 students in a school is 42 kg. If the weight of the teacher is included, the mean rises by 400 g. Find the weight of the teacher (in kg).
20.
Ram aims to score an average of 80 marks in quarterly and half yearly exams. But his average in quarterly is 3 marks less than his target and that in half-yearly is 2 marks more than his aim. The difference between the total marks scored in both the exams is 25. Total marks aimed by Ram is