If k is parallel to l find the value of a and the value of b.

a = 30

b = 40

C

Step-by-step explanation:

This requires that you use a proportion.

a / (a + 15) = 40 / 60

The small triangle's sides are in proportion to the large triangles sides.

Reduce the right. Divide top and bottom by 20

a/(a + 15) = 40/20 // 60/20

a/(a + 15) = 2/3                    

Cross multiply

3a = 2(a + 15)            Remove the brackets on the right.

3a = 2a + 30

Subtract 2a from both sides

3a-2a = 30

a = 30

Find B

b is done exactly the same way.

b/(b+20) = 2/3

3b = 2b + 40

3b - 2b = 40

b = 40

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.