30 points and brainiest ! i need a complicated number ! also the number can not be limited

Ask somebody to think of a number and keep it secret.

Then ask that person to double the secret number and then multiply by 5.  

Ask for the total.

Whatever the total is, knock off the last digit  

and you will have the secret number the person mentally chose at the start.

Hope that helps!

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.