4. SHOW YOUR WORK: Evaluate the arithmetic series.
12 + 21 + 30 + 39..., n = 15

i got -1 3/13

Step-by-step explanation:

i just used a calculator im not entirely sure if that's the answer you're looking for but.. i 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.

x= 3^y

step-by-step explanation: