SOLUTION: There are 9 sweets in a box.
There are "n" jelly beans and the rest are cola bottles.
Colin takes 2 sweets out of the box at random.
Write an expression for the probability o
Algebra ->
Probability-and-statistics
-> SOLUTION: There are 9 sweets in a box.
There are "n" jelly beans and the rest are cola bottles.
Colin takes 2 sweets out of the box at random.
Write an expression for the probability o
Log On
Question 1136068: There are 9 sweets in a box.
There are "n" jelly beans and the rest are cola bottles.
Colin takes 2 sweets out of the box at random.
Write an expression for the probability of getting 2 jelly beans.
Could you please help me with this question because I have never learnt this before in school and it is on my homework so please can someone help
I have no clue where to start Found 2 solutions by Boreal, ikleyn:Answer by Boreal(15235) (Show Source):
You can put this solution on YOUR website! n jelly beans
9-n cola bottles
probability first is a jelly bean is (n/9)
probability second is also a jelly bean is now (n-1)/8 since there is one less sweet total and one less jelly bean
The product is n(n-1)/72 and that is the probability.
suppose there are 3 jelly beans and 6 cola bottles
then the probability is 3/9*2/8=1/12
n*(n-1)/72=6/72=1/12
if n < 2 then the probability under the question is 0 (zero, ZERO);
otherwise (i.e. if n >= 2) the probability is = .
First line answer/option is clear, and I am sure, it does not require further explanations.
Second line answer/option is based on the fact, that at the first taking the probability to get a jelly bean is n of 9 items,
while the probability to get a jelly bean at the second taking is (n-1) of remaining 8 items.
The probabilities at the first and the second taking are INDEPENDENT EVENTS, so we multiply the probabilities of each event.
Congratulations: You obtained the full and complete solution with explanations.
