Q29 of 52 Page 1

Two cards are drawn simultaneously (or successively without replacement) from a well shuffled pack of 52 cards. Find the mean and variance of number of kings.

Let X be the number of kings drawn. Then X can be 0,1 or 2.






Sum of probabilities of all possible values of X is equal to 1.


Hence X is a random variable.


The mean of X is defined as, , where xi is the value of random variable and pi is the probability of that value of random variable.


Hence,


The variance of X is defined by the formula , where and .



Hence,


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Find the vector and cartesian equations of a plane passing through the points (2,2,-1), (3,4,2) and (7,0,6). Also, find the vector equation of a plane passing through (4,3,1) and parallel to the plane mentioned above.

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