Question

Jessica has 20 pieces of candy in a bag: 2 mint sticks, 9 jelly treats, and 9 fruit tart chews. If she eats one piece every 10 minutes, what is the probability her first two pieces will both be jelly treats?

Answer 1

18/95

Explanation:

Given data

2 mint sticks,

9 jelly treats, and

9 fruit tart chews.

Sample space = {2+9+9} = 20

N/B this is done without replacement since the candy are eaten Hence after each selection the candy and the sample size reduces

1.The probability of eating the first jelly treat = 9/20

2.The probability of eating the first jelly treat = 8/19

Hence the probability of her first two pieces will both

be jelly i= 9/20*8/19= 72/380

= 18/95

Answer 2

18.95%

Explanation:

In this case what we must do is calculate the probability of eating a jelly treats first and then another jelly treats, being the final probability the multiplication of these events.

We know that there are 20 in total and that initially there are 9 jelly treats, so the first event is the probability:

9/20

And the second event, with one less in each, would be:

8/19

The final probability then:

9/20 * 8/19 = 0.1895

So the probability of this happening is 18.95%