Question

Misha used a probability simulator to pull 3 colored marbles from a bag and flip a coin 50 times. The results are shown in the tables below:




Color of
Marble

Number of
Times Rolled



Blue

20


Green

18


Yellow

12





Heads

Tails



28

22



Using Misha's simulation, what is the probability of pulling a blue marble and the coin landing tails up?

Answer 1

Answers 410/2500 440/2500
32/50 and 42/50

Answer 2

MEDAL!!!

Answer 3

Here's the plan:
1. Figure out the probability of getting a blue marble based on the tables.
2. Figure out the probability of getting tails on the coin based on the tables.
3. To get the probability of blue marble AND tails on the coin, we multiply our answers to step 1 and 2.

Answer 4

uh ok

Answer 5

So, let's drill into the first part. "Probability of getting a blue marble."
How many blue marbles did Misha get? Look at the table to find this.

Answer 6

20

Answer 7

Perfect! Next, we need to know how many marbles TOTAL there were.

Answer 8

50

Answer 9

That's right! So, the probability of getting a blue marble is found by taking:

blue/total = 20/50 = 0.4

We just finished step 1.

Answer 10

ok

Answer 11

Now, for step 2, we basically do the same thing.
How many tails were there?
How many coin flips total?

Answer 12

22

Answer 13

Good on the tails. And if I'm counting correctly, I think there are 50 coin flips total.

Answer 14

yes your right

Answer 15

So that gives us

tails/total = 22/50 = 0.44

Step 2 is done. Almost finished!

Answer 16

xd ok

Answer 17

Now, to get the probability of both happening (AND), we need to multiply the probabilities (if you are doing an OR problem, you would add the probabilities):

So, we just have 0.4 * 0.44 = 0.176.

Answer 18

Unfortunately, they were mean and gave us fraction answers, but all we do is stick them in the calculator and see which one is 0.176.

Answer 19

ok

Answer 20

And, with some number punching....... Aha! Looks like it is 440/2500 = 0.176.

Answer 21

oh ok yes thank you so much

Answer 22

You are welcome. Nice work!

Answer 23

ty you too here a medal