If Mark takes 7 hours to paint a house and Hanna takes 5 hours to paint the same house, how much time will it take both of them to paint the house? Please explain!

2 hours and 42 minutes

Step-by-step explanation:

we can see that both people are painting the same house, however 1 person goes faster than the other one

lets start by putting our numbers into fractions then finding a like value. 35 in this case. 1/7 equals 5/35 and 1/5 equals 7/35 now we add these together and get 13/35. our next step is to flip this to 35/13 and take put any whole numbers. in this case 2 whole numbers can be made

leaving

9/13

(0.69)

converting this to minutes is 42 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.