There are 4 red balls and 6 black balls in a bag. Draw consecutively 3 balls with replacement. Find the probability when the first two balls drawn are black and the third ball drawn is red.

Step-by-step explanation:

So the first two balls are black, so the way to change the path is to take two out of six black balls over two out of ten balls, which is 1/3.

If the last one is red then the probability is that if you take one of the four red balls and you take one of the eight balls, you get 1/2.

So the total probability is 1/3 times 1/2 is 1/6.

$12. that is my answer.

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional