Question 1 :
The average age of $8$ persons in a committee is increased by $2$ years when two men aged $35$ years and $45$ years are substituted by two women. What is the average age of these two women ?
Question 2 :
Find the average of all the number between $6$  and $34$  which are divisible by  $5$.
Question 3 :
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?
Question 5 :
The sum of $12$ observations is $600$ then their mean is _____
Question 6 :
The daily sale of kerosene (in litres) in a ration shop for six days is as follows : $75$, $120$, $12$, $50$, $70.5$ and $140.5$ The average daily sale is
Question 8 :
The average grade of a section of $20$ students is $66\%$ and that of another section of $15$ students is $70\%$. What is the combined mean grade?
Question 9 :
The age of $13$ school students are listed below. Find the median.<br/>$12, 9, 8, 13, 15, 14, 6, 18, 7, 11, 9, 14, 10$<br/>
Question 10 :
If $i < m < n$, then the median of the list ${i, m, n}$ is ____.<br/>
Question 11 :
The median $31, 16,19, 25, 14, 13,12, 4, 28, 45$ is 
Question 12 :
Means of a set of 60 values is 23 ,if 4 is added to each these values the the new mean is
Question 13 :
The mean of the squares of the first n natural numbers is
Question 14 :
Wheat was purchases in the fist year at Rs 9 / kg in second year at Rs 10/kg and in the third year at Rs 11/kg ,if each year Rs 990 were spend in purchasing wheat the average cost of wheat during the three year is nearly 
Question 15 :
If the median of $\displaystyle \frac{x}{5}$ $\displaystyle x$ $\displaystyle \frac{x}{4}$ $\displaystyle \frac{x}{2}$ and $\displaystyle \frac{x}{3}$ $\displaystyle \left ( where\, x> 0 \right )$ is $8$ then the value of $x$ would be
Question 17 :
The mean of $20$ observations is $12.5$. By error, one observation was noted as $-15$ instead of $15$. Then the correct mean is __________.
Question 19 :
The sum $\displaystyle \sum _{ r=1 }^{ 10 }{ \left( { r }^{ 2 }+1 \right) \times \left( r\ ! \right) }$ is equal to:
Question 20 :
Find the mean of the following data :<br/>$30, 32, 24, 34. 26, 28, 30. 35, 33, 25$
Question 21 :
On Thursday, $20$ of the $25$ students in a chemistry class took a test and their average (arithmetic mean) was $80$. On Friday, the other $5$ students took the test and their average (arithmetic mean) was $90.$ What was the average for the entire class?
Question 22 :
The average of $6$ observations is $12$. A new seventh observation is included and the new average is decreased by $1$. The seventh observation is
Question 23 :
If different values of variable $x$ are $9.8, 5.4, 3.7, 1.7, 1.8, 2.6, 2.8, 8.6, 10.5\ and\ 11.1$; find the mean.<br/>
Question 24 :
The mean of $\displaystyle x_{1},x_{2}$...$\displaystyle x_{50}$ is M, if every $\displaystyle x_{i},=1,2$...50 is replaced by $\displaystyle x_{i}/50$ then the mean is
Question 25 :
The mean of the following data is :<br/>$45, 35, 20, 30, 15, 25, 40$<br/>
Question 26 :
A cricketer whose bowling average is 12.4 runs per wicket, takes 5 wicket for 26 runs and thereby decreases his average by 0.4. The number of wickets taken by him till the last match was : 
Question 27 :
The mean of $6$ numbers is $42$. If one number is excluded, the mean of remaining numbers is $45$. Find the included number. 
Question 28 : <table class="wysiwyg-table"><tbody><tr><td><u>No of students</u></td><td><u>Marks</u></td></tr><tr><td>10</td><td>80</td></tr><tr><td>5</td><td>75</td></tr><tr><td>5</td><td>70</td></tr><tr><td>2</td><td>60</td></tr><tr><td>2</td><td>55</td></tr><tr><td>1</td><td>20</td></tr></tbody></table>This question and the next refer to the above table showing the distribution of marks obtained in a Math test by a certain class <br>What is the difference between the mode and the median of the set of scores shown in the table above?
Question 29 :
The average weight of $3$ men A, B, and C in a group is $84$kg. Another man D joins the group and the average weight now becomes $80$kg. Another man E, whose weight is $3$ kg more than that of D, replaces A and the average weight of the group (B, C, D and E) becomes $79$ kg. The weight of A is
Question 30 :
Seven of the eight numbers in a distribution are $11, 16,6, 10, 13, 11, 13.$<br/> Given that the mean of the distribution is $12$,if 12 will be included then find the new mean of the distribution. 
Question 31 : The heights of students are given below.<br/><table class="wysiwyg-table"><tbody><tr><td>Height ($cm$)</td><td>$141$</td><td>$142$</td><td>$144$</td><td>$145$</td><td>$148$</td><td>$150$</td></tr><tr><td>Number of students</td><td>$7$</td><td>$11$</td><td>$10$</td><td>$12$</td><td>$20$</td><td>$13$</td></tr></tbody></table>Find the mode of the height.
Question 32 :
The average weight of the students of a class is $60\: kg$. If eight new students of average weight $64\: kg$ join the class, the average weight of the entire class becomes $62\: kg$. How many students were there in the class initially?
Question 33 :
Given the following data set, what is the value of median (2 4 3 6 1 8 9 2 5 7 ).
Question 34 :
The average salary of all the workers in a workshop is Rs. $8000$. The average salary of $7$ technicians is Rs. $12000$ and the average salary of the rest is Rs. $6000$. The total number of workers in the workshop are
Question 35 :
If the mean of five observations $x, x+2, x+4, x+6$ and $x+8$ is 11, then the mean of last three obsevations is
Question 36 :
A company produces on an average $4000$ items per month for the first $3$ months. How many items it must produce on an average per month over the next $9$ months, to average $4375$ items per month over the whole?
Question 37 :
In a triangle, the side lengths are $a = 5, b = 3$ and $c = 2$. Find the length of the median drawn to the side $c$.<br/>
Question 38 : Calculate Mode salary from the following frequency distribution:<br><table class="wysiwyg-table"><tbody><tr><td>X in Rs. (000)</td><td>10-20</td><td>20-30</td><td>30-40</td><td>40-50</td><td>50-60</td><td>60-70</td></tr><tr><td>Y Frequency</td><td>2</td><td>3</td><td>6</td><td>5</td><td>2</td><td>2</td></tr></tbody></table>
Question 39 :
If the average weight of $6$ students is $50$ kg, that of $2$ students is $51$ kg and that of rest of $2$ students is $55$ kg, then the average weight of all the students is
Question 40 : Find the value of p, if the mean of the following distribution is 7.5.<br><table class="wysiwyg-table"><tbody><tr><td>x</td><td>3</td><td>5</td><td>7</td><td>9</td><td>11</td><td>13</td></tr><tr><td>f</td><td>6</td><td>8</td><td>15</td><td>p</td><td>8</td><td>4</td></tr></tbody></table><br>
Question 41 :
The sum of the series $\displaystyle \sum_{r = 0}^{n} (-1)^{r}\ ^{n}C_{r} \left (\dfrac {1}{2^{r}} + \dfrac {3^{r}}{2^{2r}} + \dfrac {7^{r}}{2^{3r}} + \dfrac {15^{r}}{2^{4r}} + ... m\ terms \right )$ is<br>
Question 42 :
What is the modal value for the numbers $5, 8, 6, 4, 10, 15, 18, 10$?
Question 43 :
The most frequently occurring data value in a data set is the __________.
Question 44 : The frequency distribution of marks obtained by $28$ students in a test carrying $40$ marks is given below<br><table class="wysiwyg-table"><tbody><tr><td>Marks</td><td>0-10</td><td>10-20</td><td>20-30</td><td>30-40</td></tr><tr><td>Number of students</td><td>6</td><td>$x$</td><td>$y$</td><td>6</td></tr></tbody></table><br>If the mean of the above data is $20$, then the difference between $x$ and $y$ is
Question 45 :
The captain of a cricket team of $11$  players is $25$ years old and the wicketkeeper is $ 3$ years older than the captain. If the ages of these two are excluded, the average age of the remaining players in  $1$ year less than the average age of the whole team. The average of the whole team is
Question 46 :
If the values $1, \dfrac{1}{2}, \dfrac{1}{3}, \dfrac{1}{4}, \dfrac{1}{5},....\dfrac{1}{n}$ occur at frequencies $1, 2, 3, 4, 5, 6..., n$ respectively, in a frequency distribution, then the mean is
Question 47 :
If the arithmetic mean of first $n$ natural numbers is $15$, then $n$ is equal to:
Question 49 :
Find the median of the given mentioned observation $15, 20, 45, 30, 60, 36$.
Question 50 :
The mean age of 30 student is 9 years. If the age of their teacher is included, it becomes 10 years. The age of teacher ( in years ) is
Question 51 :
The value of $\sum_{n= 0}^{88}\dfrac{1}{cos\,  nk.cos \, (n +1)\,  k}$, where k is $1^o$ is equal to<br/>
Question 52 :
When there are 2 observations in the middle, median is calculated by ______.
