An ice cream store is conducting a survey asking customers to rank the top 5 out of 10 new flavors introduced this year. how many possible arrangements exist?

Which recursive formula can be used to determine the total amount of money earned in any year based on the amount earned in the previous year? f(n+1)=f(n)+5

Jenisey has $24 to spend on seven pencils. after buying them she had $10. how much did each pencil cost.?

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.