Calculate the surface area of the pyramid.

972 in^2

Step-by-step explanation:

BOTTOM: 18^2 = 324 in^2

SIDES: (18/2) * 18 = 9 * 18 = 162 in^2 * 4 = 648 in^2

TOTAL: 324 + 648 = 972 in^2

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.

they will manufacture 8496 cars