Final answer:
The probability of landing on an odd-numbered piece exactly 6 times in 20 spins is calculated using the binomial probability formula, with a probability of success on a single trial being 3/5.
Step-by-step explanation:
The problem is asking us to calculate the probability of landing on an odd-numbered piece exactly 6 times in 20 spins of a spinner divided into 5 equal pieces and numbered one to five. This is a binomial probability problem where we need to identify the number of successes (landing on an odd number), the number of trials (spins), and the probability of success on a single trial.
There are three odd numbers (1, 3, and 5) on the spinner, so the probability of landing on an odd number in one spin is 3/5. The probability of landing on an even number (2 or 4) would therefore be 2/5. Since we want exactly 6 successes (odd numbers) in 20 spins, we can use the binomial probability formula:

Where:
- n is the number of trials (spins), which is 20
- k is the number of successful trials (6)
- p is the probability of success on a single trial (3/5)
- 1-p is the probability of failure on a single trial (2/5)
Substituting the values into the formula gives us:

Calculating this probability will give us the answer to the question.