A bag contains 9 black marbles and 1 white marble.

What is the probability of the event that is complementary to the event of drawing a black marble from the bag?

a. 1/10

b. 1/9

c.8/9

d.9/10

Ellie the answer is b

No,

P(black) = 9/10
1 - 9/10 = 1/10

B is the odds of drawing a white, not the probability.

To find the probability of the complementary event, we first need to find the probability of the original event (drawing a black marble) and subtract it from 1.

The probability of drawing a black marble can be found by dividing the number of favorable outcomes (9 black marbles) by the total number of possible outcomes (10 marbles in total, since there are 9 black marbles and 1 white marble).

Probability of drawing a black marble = Number of black marbles / Total number of marbles = 9/10

Now we can find the probability of the complementary event by subtracting the probability of drawing a black marble from 1.

Probability of the complementary event = 1 - Probability of drawing a black marble = 1 - 9/10 = 1/10

Therefore, the correct answer is (a) 1/10.