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Mathematics · 2022 · 2 marks
CBSE 2022 · Region 4 · Set 1 · Q2
A coin is tossed twice. The following table shows the probability distribution of number of tails: (a) Find the value of K. (b) Is the coin tossed…
A coin is tossed twice. The following table shows the probability distribution of number of tails :
| X | $\displaystyle 0$ | $\displaystyle 1$ | $\displaystyle 2$ |
| P(X) | K | $\displaystyle 6$ K | $\displaystyle 9$ K |
(a)
Find the value of K.
(b)
Is the coin tossed biased or unbiased ? Justify your answer.
Marking-scheme solution
\(\displaystyle 16 K=1 \quad\) Let \(\displaystyle P(T)=p\) and \(\displaystyle P(H)=q\)
(a) \(\displaystyle K=\frac{1}{16}\)
(b) \(\displaystyle P(0)=\frac{1}{16}, P(1)=\frac{6}{16}, P(2)=\frac{9}{16}\)
\(\displaystyle q=\frac{1}{4} \Rightarrow p=\frac{3}{4}\)
Since \(\displaystyle P(H) \neq P(T)\), the coin, so tossed, is biased.More from Probability
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