In the number 2,145,857 how does the digit 5 in the thousands place compare to the digit 5 in the tens place

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Refer to interactive solution 17.45 to review a method by which this problem can be solved. the fundamental frequencies of two air columns are the same. column a is open at both ends, while column b is open at only one end. the length of column a is 0.504 m. what is the length of column b?

What percent of the circle below is shaded?