Guys i really need the christina is randomly choosing three movies to take on vacation from nine action movies, seven science fiction movies, and four comedies. which statement is true? the probability that christina will choose three comedies can be expressed as .1/ 4^c3 the probability that christina will choose three action movies can be expressed as .20^c3/ 9^c3 the probability that christina will not choose all comedies can be expressed as 1 − 4^c3/ 20^c4. the probability that christina will not choose all action movies can be expressed as 1 − 9^c3/20^c3

Last option is the correct answer.

Step-by-step explanation:

Total number of movies = 9+7+4=20

The total number of combinations of choosing 3 movies from total 20 is represented by  20C3. Then there are 9 action movies and we're choosing 3, the number of combinations will be 9C3,

Now, the probability of choosing all action movies will be:

As we know that probability of something which is not happening is given as : 1 - probability of something happening, so the probability of not choosing all action movies is given by:

Hence, option D or last option is the right one.

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)

7,24

step-by-step explanation: