Help on Pre-Calc Homework (Probability)

So, I need help on this question, if anyone could help and explain that'd be greatly appreciated.

Find the probability of getting two green lights in a row out of five traffic signal lights. Assume red, green, and yellow are equally likely occurences.

(It's mutiple choice, but I'd really appreciate if you could explain it, my teacher already said he wouldn't help ANYONE on this because 3/4's of our class didn't do their assignment.)

A.) 4/81 B.) 80/243 C.) 2/5 D.) 32/243

Thanks Guys!


I know it's kinda stupid to come online to ask help on my homework, but oh well =/

im in precalc and i have no idea what this means

Quote:

---

Originally Posted by chris_cr33p

im in precalc and i have no idea what this means

---

Hahaha, it's actually statistics, but we're being taught this in pre-calc.

So the probability of getting the first green light is 1/3.
Then the chance of getting the second one in a row would also be 1/3
The probability of this is 1/9 (1/3*1/3)
But your chances are greater than that because you have the chance to get 2 in a row 4 times...

...Still thinking...

Quote:

---

Originally Posted by RockonitsAjay

So the probability of getting the first green light is 1/3.
Then the chance of getting the second one in a row would also be 1/3
The probability of this is 1/9 (1/3*1/3)
But your chances are greater than that because you have the chance to get 2 in a row 4 times...

...Still thinking...

---

That's kinda how I started out, but I got lost after that... Thanks for trying! :)

Quote:

---

Originally Posted by Fir3

That's kinda how I started out, but I got lost after that... Thanks for trying! :)

---

From what I have my best guess would be A 4/81 because it has the 4 (from the four chances to get 2 consecutively) and 81 which is the 9*9

I'm really wishing I can solve this haha
Reminds me of math team from high school. No shame.

EDIT: Never mind I think your chances are greater than 5%

Well I have until Tuesday, so we'll see if someone can come up with the answer, but my guess was A also.

Quote:

---

Originally Posted by Fir3

Well I have until Tuesday, so we'll see if someone can come up with the answer, but my guess was A also.

---

Well gl.
Want to help me study for my 5 exams this week?
I'm solving your math problem instead of studying and I'm a Sociology major lol.

Quote:

---

Originally Posted by RockonitsAjay

Well gl.
Want to help me study for my 5 exams this week?
I'm solving your math problem instead of studying and I'm a Sociology major lol.

---

If you want to pass any of your exams, I better not.. Haha!

lllllllllllllllol