20 Questions
| Total Attempts: 889

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Questions and Answers

- 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
- A.
30 yr

- B.
38 yr

- C.
40 yr

- D.
42 yr

- 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?
- A.
21

- B.
35

- C.
7

- D.
14

- 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.
- A.
36.12

- B.
30.66

- C.
29.28

- D.
38.21

- 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:
- A.
35 km/h

- B.
- C.
30 km/h

- D.

- 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
- A.
135

- B.
134

- C.
180

- D.
150

- 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?
- A.
228 kg

- B.
122 kg

- C.
232 kg

- D.
242 kg

- 7.
- A.
45 kg

- B.
47.9 kg

- C.
49.9 kg

- D.
50.1 kg

- 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:
- A.
15

- B.
45

- C.
48

- D.
60

- 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.
- A.
40%

- B.
50%

- C.
55%

- D.
60%

- 10.The average of the first 100 positive integers is:
- A.
100

- B.
51

- C.
50.5

- D.
49.5

- 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:
- A.
24

- B.
42

- C.
54

- D.
60

- 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
- A.
19 yr

- B.
19 yr 6 months

- C.
20 yr

- D.
20 yr 6 months

- 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
- A.
15.2 yr

- B.
16 yr

- C.
16.2.yr

- D.
16.4 yr

- 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
- A.
58

- B.
56

- C.
50

- D.
46

- 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?
- A.
40

- B.
60

- C.
65

- D.
70

- 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
- A.
20 yr

- B.
15 yr

- C.
10 yr

- D.
8 yr

- 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
- A.
60 yr

- B.
58 yr

- C.
56 yr

- D.
55 yr

- 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
- A.
3 yr

- B.
2 yr

- C.
- D.
1 yr

- 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).
- A.
66

- B.
56

- C.
55

- D.
57

- 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
- A.
380

- B.
400

- C.
410

- D.
420