Question

In a musical chair game, the person playing the music has been advised to stop playing the music at any time within 2 minutes after she starts playing. What is the probability that the music will stop within the first half-minute after starting?

Answer 1

Hi, Total time 120 sec. Given time 30 sec.  Probability  30/120 = 1/4  Hope it helps you......

Answer 2

Solution :-

Here the possible outcomes are all the numbers between 0 amd 2. This is the portion of the number line from 0 to 2.

Lets Solve :-

Let E be the event that 'the music is stopped within the first half-minute'.

➛ The outcomes favourable to E are points on the number line from 0 to $\dfrac{1}{2}$.

➛ The distance from 0 to 2 is 2, while the distance from 0 to $\dfrac{1}{2}$ is $\frac{1}{2}$.

⠀

⠀

Since all the outcomes are equally likely, we can argue that, of the total distance of 2, the distance favourable to the event E is $\dfrac{1}{2}$.

So,

P(E)=$\dfrac{distance \: favourable \: to \: the \: event \: E}{total \: distance \: in \: which \: outcomes \: can \: lie} \\ \\ = \dfrac{ \fdrac{1}{2} }{2} = \frac{1}{4}$

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According to NCERT, this question is not from the examination point of view.