A die is rolled 20 times and the number of twos that come up are tallied. find the propabilty of getting exactly four twos

Question

anonymous · Answer

A. 0.202  
 
 B. 0.075  
 
 C. 0.101  
 
 D. 0.083

anonymous · Answer

which one would it be?

anonymous · Answer

that was wrong
it would be 
$$\dbinom{20}{4}(\frac{1}{6})^4(\frac{5}{6})^{16}$$

anonymous · Answer

reasoning that you got 4 two, each of which has probability $\frac{1}{6}$ and therefore 14 not two each with probability $\frac{5}{6}$ and $\binom{20}{4}$ different was to get that

anonymous · Answer

i keep thinking 14 but of course 20 - 4 = 16

anonymous · Answer

but i needed it round it to a deciaml yaa now(:

anonymous · Answer

http://www.wolframalpha.com/input/?i=20+choose+4+%281%2F6%29^4%285%2F6%29^16

anonymous · Answer

.2022 it looks like

anonymous · Answer

go with answer 1

anonymous · Answer

yes(: haaaa thanks so muuch(: .
wanna help me with another ?

anonymous · Answer

on line class?

anonymous · Answer

yeah sure

anonymous · Answer

yeaaah lol

anonymous · Answer

Two marbles are drawn without replacement from a box with 3 white, 2 green, 2 red, and 1 blue marble. Find the probability. The second marble is white given the first marble is blue.

anonymous · Answer

A. 
  
 
 B. 
  
 
 C. 
  
 
 D.

anonymous · Answer

it has to be a fraction

anonymous · Answer

oh this we just think
one marble is gone, it was a blue one
there are now 7 marbles in the bag, 3 are white 
$$\frac{3}{7}$$

anonymous · Answer

hope that is an answer choice, and it was much easier to compute than the last one

anonymous · Answer

thanks so much(: i hate all this math bullpellet its hardd .

anonymous · Answer

yeah probability can be a pain but you have to admit the last one didn't require much right? 
7 marbles left, 3 are white? not like the last one

anonymous · Answer

haa yeaah way less harder(: