Ron was 8 hats.
4 are blue and 4 are red
8 - 4 = 4
<u><em>20</em> palindromes exist that qualify this criteria rigorously</u>
Examples:
52025, 52125, 52225, 52325, 52425, 52525, 52625, 52725, 52825, 57975 etc.
The formula is a permutation in which n represents the sample points in the set, while r represents the number of sample points in each permutation.
Answer: the fourth one
Step-by-step explanation:
