1/2+1/2 could be a possibility.
<h3>
Answer: 1/12</h3>
=========================================================
Explanation:
There are 3 red out of 9 total
The probability of picking red at random is 3/9 = 1/3
If the first marble is not put back, then the chances of picking red again are now 2/8 = 1/4
Notice how I subtracted 1 from the numerator and denominator of 3/9 to get to 2/8. This is because the red count and the total count both go down by 1 each.
Now multiply the fractions mentioned:
(3/9)*(2/8) = (1/3)*(1/4) = (1*1)/(3*4) = 1/12
If you did this trial 12 times, then you should expect to get two reds about once. That's one way to interpret the probability of 1/12.
Side note: 1/12 = 0.0833 = 8.33% approximately
The incorrect answer is B.
All you have to do is plug in x to the formulas and see if the are equal.
4x - 2 = 3x + 6
4(8) - 2 = 3(8) + 6
30 = 30
CORRECT
The second is not only not equal, but it is the wrong kind of formula for what you are trying to prove there.
Hope that helps!
