Multiple Choice QuestionsThe arithmetic mean of 100 observations is 24.6 is added to each of the observations and then each of them is multiplied by 2.5. Find the new arithmetic mean.
30
75
35
35
Sachin Tendulkar has a certain average for 11 innings. In the 12th innings, he scores 120 runs and thereby increases his average by 5 runs. His new average is
60
62
65
65
The average of 11 results is 50. If the average of the first six results is 49 and that of the last six is 52, the sixth result is
48
50
52
52
The batting average for 40 innings of a cricketer 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 runs. The highest score of the player is
165
170
172
172
The average of three numbers is 154. The first number is twice the second and the second number is twice the third. The first number is
264
132
88
88
The average salary of all the staff in an office of a corporate house is ₹ 5,000. The average salary of the officers is ₹ 14,000 and that of the rest is ₹ 4,000. If the total number of staff is 500, the number of officers is
10
15
25
25
Of three numbers, the second is thrice the first and the third number is three-fourth of the first. If the average of the three number is 114, the largest number is
72
216
354
354
The average marks of 40 students in an English exam is 72. Later it is found that three marks 64, 62 and 84 were wrongly entered as 68, 65 and 73. The average after mistakes were rectified is
70
72
71.9
71.9
Out of nine persons, 8 persons spent ₹ 30 each for their meals. The ninth one spent ₹ 20 more than the average expenditure of all the nine. The total money spent by all of them was
₹ 260
₹ 290
₹ 292.50
₹ 292.50
In a school with 600 students, the average age of the boys is 12 years and that of the girls is 11 years. If the average age of the school is 11 years and 9 months, then the number of girls in the school is
450
150
250
250
B.
150
Average age of school is 11 years, 9 months
Average age of boys 12 years.
Average age of girls is 11 years.
Now,
Take difference to find out ratio:
(12 years -11 years + 9months) : (11 years - 11 years + 9 months))
3 months : 9 months
Therefore,
Boys : Girls
9 : 3 = 3 : 1
Switch
