In a class, the averages score of girls in an examination is 73 and that of boys is 71. The average score for the whole class is 71.8.
The percentage of the girls in the class is :
60%
40%
1.8%
18%
The mean of 1,7,5,3,4 and 10 is m. The mean of 10,12,3,5,1,7 and P is m + 1 and their median is q. Then q is equal to :
4
5
10
12
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 :
11.5
11.4
11.3
11.0
In a hockey championship there were 153 matches played. Every two teams played one match with each other. The number of teams participating in the championship is:
18
19
17
16
The average (arithmetic mean) of x and y is 40. If z = 10. Then what is the average of x, y and z?
16 2/3
30
25
17 1/2
In the first 10 over of a cricket game, the run rate was only 3.2. What should be the run rate in the remaining 40 over to reach the target of 282 runs?
6.25
6.50
6.75
7.00
The weight in kilograms of 10 students is 52, 45, 31, 35, 40, 55, 60, 38, 44, and 36. If 44 is replaced by 46 and 40 is replaced by 35 then the new median will be:
42
40.5
40
41.5
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:
12.5 years
12.7 years
12.8 years
12.9 years
Of the three numbers, the first is twice the second and the second is twice the third. The average of these numbers is 21. Find the largest number out of these:
36
38
47
48
The average of three numbers is 135. The largest number is 180 and the difference between the others is 25. The smallest number is:
130
125
120
100
A car owner buys petrol at Rs. 7.50, Rs. 8.00 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:
Rs.8
Rs.9
Rs.7.98
Rs.8.50
A demographic survey of 100 families in which two parents were present revealed that the average age A, of the oldest child is 20 years less than ½ the sum of the ages of the two parents. If F represents the age of one parents and M the age of the other parent, then which of the following is equivalent to A?
F + M – 20 / 2
F + M /2 + 20
F + M /2 – 20
F + M – 10
The mean of 30 values was 150. It was detected on rechecking that one value 165 was wrong copied as 135 for the computation of the mean. Find the correct mean:
151
149
152
None of these
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 :
72
24
36
44
The average weight of 45 students in a class is 52 kg. 5 of them whose average weight is 48 kg leave the class and other 5 students whose average weight is 54 kg join the class. What is the new average weight (in kg) of the class?
51.6
52 2/3
52 1/3
None of these