Question

Forrest got a box of chocolate from Jenny. It had n different chocolates. Forrest asked Jenny how many chocolates the box has. Jenny, who is an aspiring data scientist replied, the probability of you getting a KitKat is $\frac{1}{19}$. How many chocolates are there in the box, if each chocolate brand is equally - likely and there is only one chocolate of each brand?

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Answer 1

We want to know how many chocolates are there in the box.Two ideas we use to solve this problem are

(1)In an equally likely event, all the outcomes have same probability
(2)The probability of all the outcomes added or probability of sample space is one.

Let's assume there are n chocolates in the box. We are given the probability of all the chocolates (or brands) are same (equally - likely).

Let's take that common probability as $p$. Now, if we add the probability of all the chocolates, we should get 1.

$\Rightarrow np=1\Rightarrow \frac{n\times 1}{19}=1\Rightarrow n=19$.