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PROBABILITY — Statistics STD 12 Commerce — Question

Gujarat BoardEnglish MediumSTD 12 CommerceStatisticsPROBABILITY2 Marks
Question
One number is selected at random from the first $100$ natural numbers. Find the probability that this number is divisible by $7 .$
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Answer

Here, $U=\{1,2,3, \ldots, 100\}$
One number is selected at random.
$\therefore$ Total number of primary outcomes
$n={ }^{100} C_1=100$
A = Event that the number selected is divisible by $7 .$
$A=\{7,14,21,28, \ldots, 91,98\}$
$\therefore$ Favourable outcomes for the event $A$ is $\mathrm{m}=14$.
Hence, $P(A)=\frac{m}{n}=\frac{14}{100}=\frac{7}{50}$

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