Help me with b and explain plz

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?

The amount spent on food and drink by 20 customers is shown below what is the modal amount spent and the median amount spent? 40 25 8 36 18 15 24 27 43 9 12 19 22 34 31 20 26 19 17 28

Can you divide 25 into 4 equal groups? explain why or why not.