# Math Probability

posted by .

A math class has 20 students who choose a topic from a list for an essay. How big pool is necessary for the probability of at least one duplicate to drop below fifty percent? I understand it is like the birthday problem, I just do not understand how to solve it still.

## Similar Questions

1. ### Probability

Find the conditional probability. Suppose one card is selected at random from an ordinary deck of 52 playing cards. Let A = event a queen is selected B = event a diamond is selected Determine P(B[A) How do you go about solving this …
2. ### Math - Statistics

I roll 12 4-sided dice. What is the probability that I roll at least one 2?
3. ### math

the smallest number of people in a room where the probability of two of them having the same birthday is at least fifty percent Please post under one name. The smallest class where the chance of finding two people with the same birthday …
4. ### math/probability

For some reason I can not get my head around probability. Please show me how to work the problem not just the answers. A class has 11 students who are to be assigned seating by lot. What is the probability that the students will be …
5. ### Math

A math class has 20 students who choose a topic from a list for an essay. How big pool is necessary for the probability of at least one duplicate to drop below fifty percent?
6. ### math

A high school guidance counselor conducts a survey to find the student's first choice for a college major and found that 65% of students choose math. If three students are chosen at a random, what is the probability that at least one …
7. ### Math:Probability

The probability of having homework over the weekend in math is 0.9,history is 0.6, and Spanish is 0.75. 1. What is the probability of having exactly one class that gives homework?
8. ### Finite Math

Fifty percent of students enrolled in calculus class have previously taken pre-calculus. Thirty percent of these students received an A for the calculus class, whereas twenty percent of the other students received an A for calculus. …
9. ### Math

Forty-five percent of a large class of students in Statistics are females. Suppose 28 students are selected at random from the class. Use a normal approximation with continuity correction to calculate the probability that the number …
10. ### MS.SUE DAMON REED PSYDAG PLZ HELP ON MATH PLZZZ!!!

1. The table shows the results of spinning a four-colored spinner 50 times. Find the experimental probability and express it as a decimal. P(not red) = ?

More Similar Questions