1.
The mean of 30 values was 150. It was detected on rechecking that one value 165 was wrongly copied as 135 for the computation of the mean. Find the correct mean.
2.
The average age of a group of 10 students is 15 yrs. When 5 more students joined the group the average age rose by 1 yr. The average age (in years) of the new students is
3.
The average marks of a student in 8 subjects is 87. Of these, the highest marks are 2 more than the one next in value. If these two subjects are eliminated, the average marks of the remaining subjects is 85. What is the highest score?
4.
The average of three numbers is 135. The largest number is 180 and the difference between the others is 25. The smallest number is:
5.
There are 30 student in a class. The average age of the first 10 students is 12.5 years. The average age of the next 20 students is 13.1 years. The average age of the whole class is:
6.
In three numbers, the first is twice the second and thrice the third. If the average of these three numbers is 44, then the first number is
7.
The average weight of A, B and C is 84 kg. If D joins the group, the average weight of the group becomes 80 kg. another man E who weighs 3 kg more than D replaces A, then the average of B, C, D and E becomes 79 kg. What is the weight of A?
8.
The average of 11 numbers is 10.9. If the average of the first six numbers is 10.5 and that of the last six numbers is 11.4, then the middle number is
9.
The average salary of all the workers in a workshop is 8,000. The average salary of 7 technicians is 12,000 and the average salary of the rest is 6,000. The total number of workers in the workshop is:
10.
The mean monthly salary paid to 75 workers in a factory is Rs.5,680. The mean salary of 25 of them is Rs.5,400 and that of 30 others is Rs.5,700. The mean salary of the remaining workers is
11.
The average temperature for the first four days of a week is 40.2°C and that of the last four days is 41.3°C. If the average temperature for the whole week is 40.6°C, then the temperature on the fourth day is
12.
After 5 yrs, the age of a father will be thrice the age of his son, whereas five years ago, he was 7 times as old as his son was. What are their present ages?
13.
The average age of a man and his son is 16 years. The ratio of their ages is 15 : 1 respectively. What is the son's age?
14.
A cricketer has a certain average for 10 innings. In the eleventh inning, he scored 108 runs, thereby increasing his average by 6 runs. His new average is:
15.
Average age of 36 children of the class is 15 years. 12 more children joined whose average age is 16 years. What is the average age of all the 48 children together?
16.
Of the three numbers, the first is twice the second and the second is twice the third. The average of these numbers 21. Find the largest number out of these numbers.
17.
The average monthly expenditure of a family was Rs. 2200 during the first 3 months; Rs.2250 during the next 4 months and Rs.3120 during the last 5 months of a year. If the total saving during the year were Rs.1260, then the average monthly income was
18.
Nine persons went to a hotel for taking their meals. Each of them spent Rs.12 over their meals and the ninth one spent Rs. 8 more than the average expenditure of all the nine. Total money spent by them was:
19.
The batting average of 40 innings of a cricket player is 50 runs. His highest score exceeds his lowest score by 172 runs. If these two innings are excluded, the average of the remaining 38 innings is 48. His highest score was:
20.
The average marks in Science subject of a class of 20 students is 68. If the marks of two students were misread as 48 and 65 of the actual marks 72 and 61 respectively, then what would be the correct average?
