In a family, the average age of a father and a mother is 35 yr. The average age of the father, mother and their only son is 27 yr. what is the age of the son?
12 yr
11 yr
10.5 yr
10 yr
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.
36.12
30.66
29.28
38.21
Among three numbers, the first is twice the second and thrice the third. If the average of the three numbers is 49.5, then the difference between the first and the third number is
54
28
39.5
41.5
A.
54
Let the first number = x
∴ Second number = x/2
Third number = x/3
According to the question,
∴ First number = 81
Third number = 81/3 = 27
∴ Required difference = 81 - 27 = 54
The average of 25 observations is 13. It was later found that an observation 73 was wrongly entered as 48. The new average is
12.6
14
15
13.8
The average age of 11 players of a cricket team is increased by 2 months when two of them aged 18 yr and 20 yr are replaced by two new players. The average age of the new players is
19 yr 1 month
19 yr 6 months
19 yr 11 months
19 yr 5 months
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
15
45
48
60
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 is
30 yr
38 yr
40 yr
42 yr
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?
21
35
7
14