Probability Worksheets - Free Printable

Let’s solve this step by step.

First, count the marbles:

From the picture (we’re told there are gray, white, and black marbles):

- White marbles: 2
- Black marbles: 1
- Gray marbles: 4

Total marbles = 2 + 1 + 4 = 7

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Question 1: Which color marble is least likely to be drawn from the bag?

Least likely means the smallest number of that color.

Black has only 1 → so black is least likely.

✔ Answer: black

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Question 2: What is the probability of drawing the black marble from the bag?

Probability = (number of black marbles) / (total marbles) = 1/7

✔ Answer: 1/7

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Question 3: What is the probability of drawing a gray marble?

Gray marbles = 4 → Probability = 4/7

✔ Answer: 4/7

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Question 4: What is the probability of drawing a white marble?

White marbles = 2 → Probability = 2/7

✔ Answer: 2/7

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Question 5: What is the probability of drawing a marble that is not white?

Not white = total - white = 7 - 2 = 5 marbles (gray + black)

So probability = 5/7

✔ Answer: 5/7

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Question 6: Would you be more likely to draw a marble that is not black or a marble that is not gray? Explain your answer.

Let’s calculate both:

- Not black = total - black = 7 - 1 = 6 → probability = 6/7
- Not gray = total - gray = 7 - 4 = 3 → probability = 3/7

6/7 > 3/7 → So you are more likely to draw a marble that is not black.

Explanation: There are more marbles that are not black (6 out of 7) than marbles that are not gray (only 3 out of 7). Since 6 is bigger than 3, “not black” is more likely.

✔ Answer: You would be more likely to draw a marble that is not black because 6 out of 7 marbles are not black, but only 3 out of 7 are not gray.

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Question 7: If three more black marbles were added to the bag, what would be the probability of drawing a black marble?

Originally: 1 black marble

Add 3 → now black = 1 + 3 = 4

Total marbles originally = 7 → add 3 → new total = 10

New probability of black = 4/10 → simplify: divide numerator and denominator by 2 → 2/5

✔ Answer: 2/5

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Final Answer:

1. black
2. 1/7
3. 4/7
4. 2/7
5. 5/7
6. You would be more likely to draw a marble that is not black because 6 out of 7 marbles are not black, but only 3 out of 7 are not gray.
7. 2/5