An unbiased coin is tossed 5 times.Suppose that a variable X is assigned the value k when consecutive heads are obtained for k = 3,4,5, otherwise X takes the value -1. Then the expected value of X, is :
Option: 1
Option: 2
Option: 3
Option: 4
An unbiased coin is tossed 5 times, so total number of outcome is 25 = 32.
Now, the probability for getting number of heads occurring simultaneously
Now expected value is
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