any one know the answers?

[Darkriftz]

Im incollege and i have been trying to figure these two probs out for a while. Can anyone help me?

11.) A raffle is being held. There were 75 tickets sold and you bought 3. Prizes will be given to the first three tickets drawn. What is the probability that you will win one prize precisely on the third draw? Give your answer as a decimal rounded to 3 places.


17) A box of 15 chocolates has 6 that are caramel, 5 that contain nuts, and 4 that are nougat. If you randomly select 3 chocolates, what is the probability that you will get all nuts? Give your answer as a fraction in lowest terms.

 

[soroban]

Hello, Darkriftz!

You can "walk" your way through these problems . . .

11.) A raffle is being held. There were 75 tickets sold and you bought 3.
Prizes will be given to the first three tickets drawn.
What is the probability that you will win one prize precisely on the third draw?
Give your answer as a decimal rounded to 3 places.

There are 75 tickets: 3 are your numbers, 72 are not.

You win one prize precisely on the third draw,
This means: the first two numbers are not any of your numbers
\(\displaystyle \;\;\)and the third is one of your three numbers.

Prob. 1^st number is not yours: \(\displaystyle \;\frac{72}{75}\)
Prob. 2^nd number is not yours: \(\displaystyle \:\;\frac{71}{74}\)
Prob. 3^rd number is one of yours: \(\displaystyle \;\frac{3}{73}\)

\(\displaystyle P(\text{win on third draw})\:=\:\frac{72}{75}\cdot\frac{71}{74}\cdot\frac{3}{73}\:=\:0.0378626\:\approx\:0.038\)

17) A box of 15 chocolates has 6 that are caramel, 5 that contain nuts, and 4 that are nougat.
If you randomly select 3 chocolates, what is the probability that you will get all nuts?
Give your answer as a fraction in lowest terms.

There are 15 chocolates: 5 with nuts, 10 without.

Prob. 1^st has nuts: \(\displaystyle \,\frac{5}{15}\)
Prob. 2^nd has nuts: \(\displaystyle \;\frac{4}{14}\)
Prob. 3^rd has nuts: \(\displaystyle \;\;\:\frac{3}{13}\)

\(\displaystyle P(\text{all nuts})\:=\:\frac{5}{15}\cdot\frac{4}{14}\cdot\frac{3}{13}\:=\:\frac{60}{2730}\:=\:\frac{2}{91}\)

 

[Denis]

"A raffle is being held. There were 75 tickets sold and you bought 3. Prizes will be given to the first three tickets drawn. What is the probability that you will win one prize precisely on the third draw?"

Soroban, looks to me like it's ok to win on 1st, 2nd and 3rd draw (3 tickets);
can win on 1st and/or 2nd, and still win precisely on 3rd; right?

 

[Darkriftz]

Thanks guys

THANKS SO MUCH GUYS and you were right i can literally "walk" Through them. Appritiate it.

-Dark