Question

Lesson over the Binomial Theorem and probability:
Find P(five tails) if five coins are tossed.
1/32
5/12
12/5
3/32

Answer 1

its that easy..

Answer 2

Think of it like this...2 sides to a coin, so there is a 1/2 chance of getting either a heads or a tails...If you flip it 5 times, you still got a 1/2 chance of getting a heads or a tails. So just do a little math (1/2)^5 and you get 1/32! :)

Answer 3

help wit one more? just checking it?

Answer 4

No problem! lol what is it? :)

Answer 5

A student guesses the answers to all 10 questions on a true/false test. What is the probability that the student gets 6 questions correct?

Wouldnt you do something along the lines of:
(r+w)^10 (r being she guess right, w being she guessed wrong)
and then have r^6 w^4

Answer 6

or should i use sigma?

Answer 7

This is the probability of getting 6 success out of ten when the prob*of success = prob* of failure = 1/2

You'll use the binomial probability:

Prob* of 6 successes out of 10 = 10!/[6!3!] (1/2)^10

So can you do the rest of the math from here?

Answer 8

how did you get the [6!3!], why wouldnt it be 4?

Answer 9

Haha oops :P lol yeah it is 4. I just hit the wrong key. My bad! :P

Answer 10

Prob* of 6 successes out of 10 = 10!/[6!4!] (1/2)^10

There. :)

Answer 11

so in fraction form it would be 105/512?

Answer 12

I believe that is correct. lol :) I didn't do the math yet...I am eating a burrito, give me a minute. :P

Answer 13

Hha no :) eat your burrito in peace :) it was right thanks so much!

Answer 14

Haha okay :P Lol no problem! Glad I could help. :)