Average height & variance of `5` students in a class is `150` and `18` respectively. A new student whose height is `156 cm` is added to the group. Find new variance. (a) `20` (b) `22` (c) `16` (d) `14`

The mean weight of 21 students is 21 kg. If a student weighing 21 kg is removed from the group, then the mean of the remaining students is (a) 20 kg (b) 21 kg (c) 19 kg (d) 18 kg

A hollow sphere of internal and external diameters 4 cm and 8 cm respectively is melted into a cone of base diameter 8 cm. The height of the cone is (a) 12 cm (b) 14 cm (c) 15 cm (d) 18 cm

The first three terms of a proportion are 12, 21 and 8 respectively. Then 4th term is (a) 18 (b) 16 (c) 14 (d) 20

Mean and variance of five observations are 4 and 5.2 respectively. If three of these observations are 3, 4, 4 then find absolute difference between the other two observations (A) 3 (B) 7 (C) 2 (D) 5

Mean and variance of five observations are 4 and 5.2 respectively. If three of these observations are 3, 4, 4 then find absolute difference between the other two observations (A) 3 (B) 7 (C) 2 (D) 5

Two bodies A (of mass 1 kg ) and B (of mass 3 kg ) are dropped from heights of 16 m and 25 m . Respectively. The ratio of the time taken to reach the ground is : (a) 5/4 (b) 12/5 (c) 5/12 (d) 4/5

The following bar graph (Figure) represents the heights (in cm) of 50 students of Class XI of a particular school. Study the graph and answer the following questions: What percentage of the total number of students have their heights more than 149 cm? How many students in the class are in the range of maximum height of the class? The school wants to provide a particular type of tonic to each student below the height of 150cm to improve his height. If the cost of the tonic for each student comes out to be Rs. 55, how much amount of money is required? How many students are in the range of shortest height of the class? State whether true or false: There are 9 students in the class whose heights are in the range of 155-159 cm. Maximum height (in cm) of a student in the class is 17. There are 29 students in the class whose heights are in the range of 145-154 cm. Minimum height (in cm) of a student is the class is in the range of 140-144cms. The number of students in the class having their heights less than 150cm is 12. There are 14 students each of whom has height more than 154 cm.

The material of a cone is converted into the shape of a cylinder of equal radius. If height of the cylinder is 5 cm, then height of the cone is (a) 10 cm (b) 15 cm (c) 18 cm (d) 24 cm

In an isosceles triangle A B C , if A B=A C=25 c m and B C=14 c m , then the measure of altitude from A on B C is (a) 20cm (b) 22cm (c) 18cm (d) 24cm

The heights (in cm) of 35 students of a class are given below : {:("Height (in cm)",157,152,153,154,155,156),("Number of students",7,4,3,5,9,7):} Find the median height.