Combinatorics

Probability simulator

Run an experiment many times for an estimate with a margin.

For checking your work after you’ve tried it yourself.

Step 1:
Set up the experiment

Dice, coins or drawing from a bag.

Step 2:
Choose the event

What you want to count.

Step 3:
Run it

Thousands of trials give an estimate with a margin.
What it does.
Repeats a random experiment many times and reports how often your event happened, with a margin of error.
When it helps.
Checking that a probability you calculated is in the right range.
What it won’t do.
It gives an estimate, never the exact answer.
Example.
Two dice summing to 7: about 0.167, close to 16\frac{1}{6}.
Set up the experiment
Trials

Each run uses a fresh random seed, shown with the result.

Try

This is an estimate from random trials, never the exact answer.