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Question
Suppose X is the number of tails occurred when three fair coins are tossed once simultaneously. Find the values of the random variable X and number of points in its inverse images
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Solution
Let X is the random variable that denotes the number of tails when three coins are tossed simultaneously.
Sample space S = {HHH, HHT, HTH, HTT, THH, THT, TTH, TTT}
∴ ‘X’ takes the values 0, 1, 2, 3
i.e., (HHH) = 0
X(HHT, HTH, THH) = 1
X(HTT, THT, TTH) = 2
X(TTT) = 3
| Values of the random variable | 0 | 1 | 2 | 3 | Total |
| Number of elements in inverse image | 1 | 3 | 3 | 1 | 8 |
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