50+ Probability worksheets for 7th Grade on Quizizz | Free & Printable - Free Printable

Let’s solve each problem one by one, step by step.

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Problem 1:

A jar has:
- 2 pink marbles
- 6 red marbles
- 4 blue marbles

Total marbles = 2 + 6 + 4 = 12

We want the probability of picking a red OR blue marble.

Number of red or blue marbles = 6 (red) + 4 (blue) = 10

Probability = favorable outcomes / total outcomes = 10 / 12

Simplify: divide numerator and denominator by 2 → 5/6

✔ So the answer is D. 5/6

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Problem 2:

The chart shows:

| Red | Yellow | Blue | Green | Brown |
|-----|--------|------|-------|-------|
| 5 | 11 | 7 | 10 | 5 |

Total marbles = 5 + 11 + 7 + 10 + 5 = let’s add:

5 + 11 = 16
16 + 7 = 23
23 + 10 = 33
33 + 5 = 38? Wait — that doesn’t match any options.

Wait — maybe I misread. Let me check again.

Actually, looking at the options: A=5/14, B=10/28, C=5/19

Hmm… perhaps the numbers are small? Maybe it's not 5,11,7,10,5?

Wait — in the image, the table might be:

Red: 5
Yellow: 11
Blue: 7
Green: 10
Brown: 5

But 5+11+7+10+5 = 38 — none of the denominators are 38.

Wait — option B is 10/28 — which simplifies to 5/14 — same as A.

Option C is 5/19.

Maybe the total is 28? Let’s see: if green is 10, and P(green)=10/28, then total must be 28.

So maybe the numbers are different? Or perhaps I misadded.

Wait — let’s recalculate with possible typo assumption.

Suppose the numbers are:

Red: 5
Yellow: 11
Blue: 7
Green: 10
Brown: 5 → still 38.

Alternatively — maybe “Brown” is not included? But the question says “the number of marbles in a jar” and lists all five.

Wait — look at option B: 10/28 — that’s exactly green over total if total is 28.

So perhaps the actual numbers are:

Let me assume the table is:

Red: 5
Yellow: 11
Blue: 7
Green: 10
Brown: ? — but 5+11+7+10 = 33 — too big.

Wait — maybe it’s:

Red: 5
Yellow: 11
Blue: 7
Green: 10
Brown: -5? No.

Perhaps the table is misread. Another possibility: maybe the numbers are smaller.

Looking back — perhaps the table is:

Red: 5
Yellow: 11
Blue: 7
Green: 10
Brown: 5 — but that’s 38.

Wait — option C is 5/19 — half of 38 is 19 — so maybe they meant something else.

Hold on — perhaps the table is:

Actually, let’s think differently.

If P(green) = 10 / total, and option B is 10/28, then total = 28.

So what adds to 28?

Suppose:

Red: 5
Yellow: 11
Blue: 7
Green: 10
Brown: -5? No.

Wait — 5 + 11 = 16; 16 + 7 = 23; 23 + 10 = 33 — already over 28.

Unless... maybe "Brown" is not part of it? But the table includes it.

Another idea: perhaps the numbers are:

Red: 5
Yellow: 11
Blue: 7
Green: 10
Brown: 5 — but that’s 38.

Wait — 38 divided by 2 is 19 — and option C is 5/19 — which would be if green was 5? But green is 10.

I think there might be a mistake in my reading.

Let me try this: perhaps the table is:

Red: 5
Yellow: 11
Blue: 7
Green: 10
Brown: 5 — total 38.

But 10/38 simplifies to 5/19 — oh! Yes!

10 ÷ 2 = 5
38 ÷ 2 = 19

So P(green) = 10/38 = 5/19

And option C is 5/19.

Yes! That makes sense.

So total marbles = 5+11+7+10+5 = 38
Green = 10
P(green) = 10/38 = 5/19

✔ Answer is C. 5/19

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Problem 3:

Bag has:
- 3 red
- 2 blue
- 4 yellow

Total marbles = 3 + 2 + 4 = 9

Probability of pulling a red = number of red / total = 3/9

Simplify: 3÷3 / 9÷3 = 1/3

But wait — options include both 3/9 and 1/3.

Option B is 1/3, Option C is 3/9.

Both are correct mathematically, but usually we simplify fractions.

In multiple choice, if both are present, pick the simplified form unless specified otherwise.

But let’s see the options:

A. 1/9
B. 1/3
C. 3/9
D. 3/10

Since 3/9 reduces to 1/3, and 1/3 is an option, likely B is expected.

But technically, 3/9 is also correct — however, in probability, we usually give simplest form.

Also, note that 3/9 is listed as option C — so perhaps they accept it.

But let’s check the bag description: “3 red, 2 blue, 4 yellow” — total 9.

P(red) = 3/9 = 1/3.

I think B. 1/3 is the best answer.

But wait — option C is 3/9 — which is unsimplified.

In many tests, they expect simplified form.

Moreover, in problem 1, they had 10/12 and chose 5/6 — simplified.

Similarly here, 3/9 should be simplified to 1/3.

✔ So answer is B. 1/3

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Problem 4:

Experimental Probability is:

Options:

A. What Will happen
B. What I think Happens
C. What actually happens
D. What should happen

Experimental probability is based on actual experiments or trials — what actually occurred when you did the experiment.

For example, if you flip a coin 10 times and get 6 heads, experimental probability of heads is 6/10.

It’s not theoretical (“what should happen”) or guesswork (“what I think”).

So correct answer is C. What actually happens

✔ Answer: C

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Problem 5:

Probability of flipping a coin and getting heads.

Assuming a fair coin, two equally likely outcomes: heads or tails.

So P(heads) = 1/2

Options:

A. 1/3
B. 1/2
C. Never. Tails never fails — this is a joke, not serious
D. 1/4

Clearly, B. 1/2

✔ Answer: B

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Final Answers:

1. D
2. C
3. B
4. C
5. B