9) The average monthly expenditure of a family for the first five months is Rs. 2580 and for the next 7 months is Rs. 3050. If the family saves Rs. 2470 during the whole year, find the average monthly salary of the family during the year.
(A) Rs. 2490
(B) Rs. 3060
(C) Rs. 3200
(D) Rs. 3080
10) Nine students of a class contribute a certain sum. Seven of them give Rs. 5 each and the other two give Rs. 5 and Rs. 9 more than the average contribution of all the 9 students. The average contribution of the class of 9 students is:
(A) Rs. 10
(B) Rs. 14
(C) Rs. 7
(D) Rs. 12
11) A batsman has a certain average of runs for 11 innings. In the 12th inning he scores 129 runs, thereby increasing his average by 9 runs. What is his average for the first 11 innings?
(A) 30
(B) 45
(C) 11
(D) 21
12) A batsman's average for a certain number of innings was 42.5, In the next four innings he scored 20, 75, 15, and 0 runs and his average for all the innings was fall by 5. How many innings did he played?
(A) 9
(B) 8
(C) 12
(D) 11
13) The average weight of 24 students of section A of class is 58.6kg whereas the average weight of 26 students of section B of the same class is 60.4kg. Find the average weight of students of both section.
(A) 59.53
(B) 57.53
(C) 56.53
(D) 49.33
14) The average of 11 numbers is 42. On including the twelfth number the average becomes 45. The twelfth number is?
(A) 78
(B) 72
(C) 68
(D) 52
15) The average of 5 numbers is 80. If one number is removed, the average becomes 50. Find the removed number.
(A) 40
(B) 70
(C) 150
(D) 200
16) If the average of 5 quantities is 8 and the average of 3 of them is 6. What is the average of the remaining two numbers?
(A) 7
(B) 10
(C) 11
(D) 13