David wants to rent a movie. He wants to watch either a comedy or a drama. The movie rental store has 18 comedies and dramas available for rent. Seven of the movies are comedies, and eleven of the movies are dramas. David has not seen two of the comedies, and he has not seen four of the dramas. If David selects a movie randomly, what is the probability the movie will be a comedy or a movie that he has not seen?
Formula: P(A or B)=P(A)+P(B)-P(A or B)
p(c)=7/18
p(s)=6/18
p(c or s)=2/18
0.39+0.33-0.11=
answer:0.61
He has not seen 5 of the comedies and 7 of the dramas
Since you want the non-seens from one OR the other
there are 12 movies he has not seen
prob(nonseen) = 12/18 = 2/3
To find the probability that David selects a comedy or a movie he hasn't seen, we need to find the total number of movies that satisfy these conditions and divide it by the total number of movies available.
1. The number of comedies David has not seen: 2
2. Number of comedies in total: 7
3. Number of dramas David has not seen: 4
4. Number of dramas in total: 11
To find the total number of movies that satisfy these conditions, we add the number of comedies David hasn't seen to the number of dramas he hasn't seen: 2 + 4 = 6.
The total number of movies available for rent is the sum of comedies and dramas: 7 + 11 = 18.
Therefore, the probability that the movie David selects is a comedy or a movie he hasn't seen is: 6 / 18 = 1/3, which can also be simplified as approximately 0.333 or 33.33%.
To find the probability of selecting a movie that is either a comedy or a movie David has not seen, we need to calculate the number of such movies and divide it by the total number of movies.
Let's break it down step by step:
Step 1: Find the number of movies that are either comedies or movies David has not seen:
- Number of comedies available: 18
- Number of dramas available: 18
- Number of comedies David has not seen: 2
- Number of dramas David has not seen: 4
Number of movies that are either a comedy or a movie David has not seen:
= Number of comedies + Number of dramas - Number of comedies David has not seen - Number of dramas David has not seen
= 18 + 18 - 2 - 4
= 30
Step 2: Find the total number of movies available for rent:
= Number of comedies + Number of dramas
= 18 + 18
= 36
Step 3: Calculate the probability:
Probability = Number of desired outcomes / Total number of possible outcomes
= Number of movies that are either a comedy or a movie David has not seen / Total number of movies available for rent
= 30 / 36
= 5 / 6
Therefore, the probability that David will select a movie that is either a comedy or a movie he has not seen is 5/6 or approximately 0.8333 (rounded to four decimal places).