A lightning discharge from a cloud 2.5 mi high is measured at a speed of 550 mi/s (miles per second) for the down stroke and 10000 mi/s for the powerful return stroke (ground to cloud). What is the total time for both strokes? Give your answer to two significant figures.

it 2

step-by-step explanation:

8^1/3=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.

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