A group of friends decided to divide the $800 cost of trip equally among themselves. When two of the friends decides not to go on the trip, those remaining still didvide the $800 cost equally , but each friends share of the cost increase by $20. How many friends were in the group orginally?

10 friends

Step-by-step explanation:

Let the initial number be x friends so that when 2 decide not to go, the remaining will be x-2. The final cost per person minus initial cost per person is $20.

Initial cost per person was

Final cost per person is

x=-8 or 10

Therefore, the original number was 10 friends

a) one student is chosen from classroom a, then a student is chosen from classroom b.  

step-by-step explanation:

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.