The mean and variance of heights of XI students are 162.6 cm and `127.69 cm^2` respectively.Find the C.V.

The mean and variance of eight observations are 9 and 9.25, respectively. If six of the observations are 6, 7, 10, 12, 12 and 13 , find the remaining two observations.

The radii of the circular ends of the frustrum of height -6cm are 14 cm and 6cm respectively. Find the lateral surface area and total surface area of frustrum.

A toy is in form of a cone mounted on a hemisphere on the same diameter . The diameter of the base and the height of the cone are 6 cm and 4 cm respectively. Determine the surface area of the toy . [use pi= 3.14 ]

The mean and variance of a binomial distribution are 4 and 2 respectively . Then the probability of 2 successes is :

The corresponding altitudes of two similar triangles are 6 cm and 9 cm respectively. Find the ratio their areas.

The heights of five runners are 160cm, 137cm, 149cm, 153cm, and 161cm respectively. Find the mean height.

A bucket is in the form of a frustum of cone and holds 28.490 litres of water. The radii of top and bottom are 28 cm and 21 cm respectively. Find the height of the bucket.

The mean and variance of a binomial distribution are 6 and 4 respectively, then n is

A solid is in the form of cone mounted on a right cylinder, both having same radii as shown in the figure. The radius of the base and height of the cone are 7 cm and 9 cm respectively. If the total height of the solid is 30 cm, find the volume of the solid.

In the figure ,A and B are the centres of two circles with radii 6 cm and 2 cm respectively .CD is the diameter then MD is equal to :