Question

plz help i will attach the question

Answer 1

by watch how other people do this, i think mine is wrong

Answer 2

Let's start with part A)

The PROBABILITIY of unlocking the treasure chest is 13/20

That means the chances of unlocking the treasure chest is 13
The total number of outcomes is 20

So if you tried 20 times, and you only unlock the treasure chest 13 times?

How many times did you NOT unlock the treasure chest?

Essentially, what is 20 - 13 = ?

Answer 3

7

Answer 4

but it has to be a fraction

Answer 5

so 7/13
??????

Answer 6

7 is how many times you would NOT unlock

Now look at the question, it's asking about the ODDS of UNLOCKING

so we want the fraction to be the other way

what are the chances of unlocking divided by the chances of not unlocking

Answer 7

7/20

Answer 8

no, remember 20 is the TOTAL

we want just the chances of not unlocking

okay okay, let's start over again

\(\sf probability = \dfrac{favorable~outcomes~}{total~outcomes} = \dfrac{favorable~outcomes}{favorable~outcome+unfavorable~outcome}\)


\(\sf odds = \dfrac{favorable~outcomes}{unfavorable~outcomes}\)

Answer 9

we said that the favorable outcomes is 13

the total outcomes is 20

which means that the unfavorable outcomes is 7

so what is the odds then?

Answer 10

7/13

Answer 11

no 13/7

Answer 12

the ODDS in favor of her unlocking the chest

= chances of unlocking / chances of NOT unlocking

so 13/7 is correct

Answer 13

ok

Answer 14

part b?

Answer 15

sure, let's get started on part b now

Answer 16

ok

Answer 17

so what would the formula be for probability

Answer 18

The ODDS against choosing a blue block is 4/7

Remember
\(\sf odds = \dfrac{favorable~outcomes}{unfavorable~outcomes}\)

4 is how many times we would NOT choose a blue block
7 is how many times we would choose a blue block

does that make sense so far?

Answer 19

yes

Answer 20

They told us the ODDS of NOT choosing a blue block

so you have to be careful to not get the numbers confused

otherwise we would have thought that the 4 is the number of times you do get a blue block
but since the odds is against that means 4 is the number of times you don't get the blue block

and 7 is the number of times you would get the blue block

Answer 21

oh ok

Answer 22

Now to find the probability of getting a blue block

\(\text{probability} = \dfrac{\text{(number of times you get a blue block)}}{\text{total times}}\)

Answer 23

so 3/7?????

Answer 24

so you know how many times you get the blue blocks

that's 7

but what is the total number of times we're choosing?

It's going to be 4 + 7

that's your denominator or the bottom part of the fraction

Answer 25

oh so 7/11

Answer 26

Yes

you want
number of times you get the blue block / total number of times


that's the PROBABILITY of getting a blue block

Answer 27

oh ok thx

Answer 28

i got it right thx]

Answer 29

no problem :)

hopefully that made sense and gives you some more clarity on this question