The average of six numbers is x and the average of three of these is y. If the average of the remaining three is z, then :
x = y + z
2x = y + z
x = 2y + 2z
none of these
The average of five consecutive numbers is n. If the next two numbers are also included, the average will :
Remain the same
Increase by 1
Increase by 14
Increase by 2
The average age of 30 students is 9 years .If the age of their teacher is included ,it becomes 10 years . The age of the teacher (in years ) is
27
31
35
40
A trader buys a chair for Rs. 600 and sells it for Rs. 765 at a credit of 4 months. Reckoning money worth 6% p.a., his gain percent is:
20%
25%
A trader mixes 26 kg of rice at Rs. 20 per kg with 30 kg of rice of other variety at Rs. 36 per kg and sells the mixture at Rs. 30 per kg. His profit percent is:
5%
8%
10%
None of these
No profit, no loss
The average weight of 8 persons increases by 2.5 kg when a new person comes in place of one of them weighing 65 kg. What might be the weight of the new person?
76 kg
76.5 kg
85 kg
Data inadequate
The average of 20 numbers is zero. Of them, at the most, how many may be greater than zero?
0
1
10
19
The captain of a cricket team of 11 members is 26 years old and the wicket keeper is 3 years older. If the ages of these two are excluded, the average age of the remaining players is one year less than the average age of the whole team. What is the average age of the team?
23 years
24 years
25 years
26 years
The average of 10 scores is 80. When the highest and the lowest scores are dropped the average is 81. If the highest score is 92, find the lowest score.
80
78
76
60
When a commodity is sold for Rs. 34.80, there is a loss of 2%. What is the cost price of the commodity?
Rs.26.10
Rs. 43
Rs. 43.20
Rs. 46.40
A family consists of two grandparents, two parents and three grandchildren. The average age of the grandparents is 67 years, that of the parents is 35 years and that of the grandchildren is 6 years. What is the average age of the family?
28 (4 / 7) years
31 (5 / 7) years
32 (1 / 7) years
35 (5 / 7) years
If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55 and 60, then the average marks of all the students is:
53.33
54.68
55
A student was asked to find the arithmetic mean of the numbers 3, 11, 7, 9, 15, 13, 8, 19, 17, 21, 14 and x. He found the mean to be 12. What should be the number in place of x ?
3
7
17
The average weight of A, B and C is 45 kg. If the average weight of A and B be 40 kg and that of B and C be 43 kg, then the weight of B is:
17 kg
20 kg
26 kg
31 kg
A banana costs Rs. 2.25 and an apple costs Rs. 3.00. What will be the total cost of 4 dozen of bananas and 3 dozen of apples?
Rs. 216
Rs. 108
Rs. 189
Rs. 225
Rs. 162
A tradesman gives 4% discount on the marked price and gives 1 article free for buying every 15 articles and thus gains 35%. The marked price is above the cost price by:
39%
40%
50%
A pupil's marks were wrongly entered as 83 instead of 63. Due to that the average marks for the class got increased by half. The number of pupils in the class is:
20
73
None of the above
The average of 10 numbers is 40.2. Later it is found that two numbers have been wrongly copied. The first is 18 greater than the actual number and the second number added is 13 instead of 31. Find the correct average.
40.1
40.4
40.6
40.8.
A family consists of two grandparents, two parents and three grandchildren. The average age of the grandparents is 67 years, that of the parents is 35 years and that of the grandchildren is 6 years. The average age of the family is
3227 years
3157 years
2817 years
3057 years
X sells 6 horses and buys 9 Cows, thus in creasing his cash by Rs 90. He then at the same prices buys 9 horses and sells 15 Cows, thus decreasing his cash by Rs 91. Find the price of each Cow.Assume he had nil balance at the start.
Rs 123
Rs 150
Rs 175
Rs 200
By selling 75 toys a shopkeeper gains the selling price of 25 toys. Find his gain percent
75%
The average of 50 numbers is 30. If two numbers, 35 and 40 are discarded, then the average of the remaining numbers is nearly:
28.32
28.78
29.27
29.68
A trader marked the price of his commodity so as to include a profit of 25%. He allowed discount of 16% on the marked price. His actual profit was;
9%
16%
Average cost of 5 apples and 4 mangoes is Rs. 36. The average cost of 7 apples and 8 mangoes is Rs. 48. Find the total cost of 24 apples and 24 mangoes.
1044
2088
720
324
The average number of printing error per page in a'bod 512 pages is 4. If the total number of printing error ml first 302 pages is 1,208, the average number of printinget per page in the remaining pages is'
4
840
90
In an examinations, a pupil’s average marks were 63 per paper. If he had obtained 20 more marks for his Geography paper and 2 more marks for his History paper, his average per paper would have been 65. How many papers were there in the examination?
8
9
11
12
Rahim buys 3 kg mangoes for Rs 21 and sells them at 5 kg for Rs 50. To earn Rs 102 as profit, the mangoes to be sold by him should be
34 kg
52 kg
32 kg
If √2 = 1.4142, the value of 7/(3 + √2) is:
1.5858
3.4852
3.5858
4.4142
The average price of 10 books is Rs. 12 while the average price of 8 of these books is Rs. 11.75. Of the remaining two books, if the books, if the price of one book is 60% more than the price of the other, what is the price of each of these two books?
Rs. 5, Rs. 7.50
Rs. 8, Rs. 12
Rs. 10, Rs. 16
Rs. 12, Rs.14
The average height of 25 boys is 1.4 m. When 5 boys leave the group, then the average height increase by 0.15 m. What is the average height of the 5 boys who leave ?
0.8 m
0.9 m
0.95 m
1.05 m