A dog slept from 10:51 p. m. to 1:22 a. m. how long does a dog sleep

2 hours and 31 minutes

Step-by-step explanation:

10:51 +9 =11:00

+ 2 hours = 1:00 +22 = end time

so added together 22+9= 31 + the 2 hours = 2 hours and 31 minutes

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.