26) in a class of 30 students, approximately what is the probability that two of the students have their birthday on the same day (defined by same day and month) (assuming it’s not a leap year)? for example – students with birthday 3rd jan 1993 and 3rd jan 1994 would be a favorable event.
Answer is 0.696
The sum number of sets possible for no two students to have the same birthday in a class of 30 is:
=30 * (30-1)/2
Now, there are 365 days in a year. Therefore, the probability of students having a birthday on a different date would be 364/365. Now there are a number of combination, to be exact 870 combinations.
So, the probability that no two students having the same birthday is:
(364/365)^435 = 0.303.
Now, the probability that two students would have their birthdays on the same equal date would be:
1-0.303 = 0.696 or 70%
a) one student is chosen from classroom a, then a student is chosen from classroom b.
independent events are ones in which the probability of one event does not affect the probability of the second event.
one student is chosen from classroom a; this does not affect the chances of choosing a student from classroom b. this makes these independent events.
when one card is chosen from a standard deck and then set aside before a second card is chosen, the probability of the second card being chosen changes. this makes them dependent events.
when one student is chosen from classroom a and then a second student is chosen from classroom a, the probability of choosing the second student changes. this makes them dependent events.
when a letter is chosen from the alphabet and then a second letter is chosen, the probability of choosing the second letter changes. this makes them dependent events.
what is the graph