Joey can paint a room in 2 hours and chelsea can paint the same room in 3 hours. if they work together how long would it take to paint the room

Step-by-step explanation:

we know that

Joey can paint a room in 2 hours

That means

Joey can paint the 100% of the room-------> 2 hours

so

In 1 hour ------> can paint 100%/2=50%

Chelsea can paint a room in 3 hours

That means

Chelsea can paint the 100% of the room-------> 3 hours

so

In 1 hour ------> can paint (100%/3)=33.33%

therefore

Joey and Chelsea in 1 hour can paint -----> 50%+33.33%=83.33%

by proportion

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.

answer is 144

step-by-step explanation: