9. Compreu dos productes i us costen 220 €. La setmana següent feu la mateixa compra i, com que el primer article està rebaixat en un 10 % i el segon un 20 % respecte a la setmana anterior, només us costa 186 €. Quant us costarà la mateixa compra si en una altra ocasió els preus estan rebaixats un 10 % i un 20 %, respectivament, en relació amb els preus de la segona setmana? (R: 157'80 €)

step-by-step explanation:

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.

a

step-by-step explanation:

the answer is a