Binomial Probability: 20 Trials, 10 Successes, p = 0.5
The probability of exactly 10 successes in 20 trials with p = 0.5 is approximately 17.6%.
How to use this tool
- Enter trials (n), successes (k) and probability of success (p) in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your p(x = k) and the full breakdown beneath it.
Find the binomial probability of exactly 10 successes out of 20 trials when each trial has a 50% chance of success.
Frequently asked questions
- What is the binomial distribution?
- The binomial distribution models the number of successes in n independent yes/no trials, each with the same probability p of success. Classic examples: coin flips, pass/fail tests.