Calculate the probability of flipping a coin 20 times and getting 4 heads. Round your answer to the nearest ten thousandth. Big ideas math

Avery’s piggy bank has 300 nickels, 450 pennies, and 150 dimes. she randomly picks three coins. each time she picks a coin, she makes a note of it and puts it back into the piggy bank before picking the next coin.

1. if events a and b are non-overlapping events, how do you find the probability that one or the other occurs? 2. what does it mean if p(a or b) equals 1?

What is the distance between the points (2, 5) and (5,9)?