three friends meet to share their rock collection sarah has two rocks Camilla has three times as many rocks as sarah zachary has four times as many rocks as Camilla​

 (if that's the question?)

SARAH:: 2 rocks

CAMILLA:: 6 rocks

ZACHARY:: 24 rocks

Step-by-step explanation:

If Sarah has 2 rocks and Camilla has 3 times as many, then Camilla has 6 rocks because 2*3= 6

And if Camilla has 6 rocks while Zachary has four times as many as Camilla, then Zachary has 24 rocks because 6*4= 24

(hope this 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.