The document contains examples of calculating averages from sets of numbers, as well as word problems involving averages. It provides formulas for calculating the average of a data set as the sum of all values divided by the number of values. It also gives a formula for calculating the average speed over a journey when distances are covered at different speeds. Several word problems then apply these concepts to scenarios involving students' exam scores, family incomes and ages, book and petrol prices, and more.
2. Formula: 1.Average=Sum of quantities/Number of quantities. 2.Suppose a man covers a certain distance at x kmph and an equal distance at y kmph ,then the average speed during the whole journey is (2xy/x+y) kmph.
3. 1.Find the average of all these numbers.142,147,153,165,157. Find the average of all these numbers.4,10,16,22,28 Find the average of all these numbers.4,10,16,22,28,34.
4. The average marks of a marks of a student in 4 Examination is 40.If he got 80 marks in 5th Exam then what is his new average. In a group the average income of 6 men is 500 and that of 5 women is 280, then what is average income of the group.
5. The average weight of a class of 30 students is 40 kgs if the teacher weight is included then average increases by 2 kgs then find the weight of the teacher? The average age of Mr and Mrs Sharma 4 years ago is 28 years . If the present average age of Mr and Mrs Sharma and their son is 22 years. What is the age of their son.
6. The average price of 10 books is increased by 17 Rupees when one of them whose value is Rs.400 is replaced by a new book. What is the price of new book? The average marks of girls in a class is 62.5. The average marks of 4 girls among them is 60.The average marks of remaining girls is 63,then what is the number of girls in the class?
7. The average of 2,7,6 and x is 5 and the average of and the average of 18,1,6,x and y is 10 .what is the value of y?
8. 1.油In the first 10 overs of a cricket game, the run rate was only 3.2. What should be the run rate in the remaining 40 overs to reach the target of 282 runs? A. 6.25 B. 6.5 C. 6.75 D. 7
10. 2.油A family consists of grandparents, parents and three grandchildren. The average age of the grandparents is 67 years, that of the parents is 35 years and that of the grandchildren is 6 years. What is the average age of the family? A. 28油4/7years B. 31油5/7years C. 32油1/7years D. None of these
12. 3.油A grocer has a sale of Rs. 6435, Rs. 6927, Rs. 6855, Rs. 7230 and Rs. 6562 for 5 consecutive months. How much sale must he have in the sixth month so that he gets an average sale of Rs. 6500? A. Rs. 4991 B. Rs. 5991 C. Rs. 6001 D. Rs. 6991
14. 15.油A pupil's marks were wrongly entered as 83 instead of 63. Due to that the average marks for the class got increased by half. The number of pupils in the class is: A. 10 B. 20 C. 40 D. 73
16. 14.油If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55, 60, then the average marks of all the students is: A. 53.33 B. 54.68 C. 55 D. None of these
18. 13.油A library has an average of 510 visitors on Sundays and 240 on other days. The average number of visitors per day in a month of 30 days beginning with a Sunday is: A. 250 B. 276 C. 280 D. 285
20. 12.油The average weight of 16 boys in a class is 50.25 kg and that of the remaining 8 boys is 45.15 kg. Find the average weights of all the boys in the class. A. 47.55 kg B. 48 kg C. 48.55 kg D. 49.25 kg
22. 11.油The average weight of A, B and C is 45 kg. If the average weight of A and B be 40 kg and that of B and C be 43 kg, then the weight of B is: A. 17 kg B. 20 kg C. 26 kg D. 31 kg
24. 6.油The captain of a cricket team of 11 members is 26 years old and the wicket keeper is 3 years older. If the ages of these two are excluded, the average age of the remaining players is one year less than the average age of the whole team. What is the average age of the team? A. 23 years B. 24 years C. 25 years D. None of these
26. 7.油The average monthly income of P and Q is Rs. 5050. The average monthly income of Q and R is Rs. 6250 and the average monthly income of P and R is Rs. 5200. The monthly income of P is: A. 3500 B. 4000 C. 4050 D. 5000
28. 8.油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: A. 35 years B. 40 years C. 50 years D. None of these
30. 9.油A car owner buys petrol at Rs.7.50, Rs. 8 and Rs. 8.50 per litre for three successive years. What approximately is the average cost per litre of petrol if he spends Rs. 4000 each year? A. Rs. 7.98 B. Rs. 8 C. Rs. 8.50 D. Rs. 9