The percent of shares Sage owns can be expressed algebraically as:
(Sage's number of shares / Total number of shares) x 100%
Since the total number of shares is represented by s, we can substitute s for the total number of shares:
(Sage's number of shares / s) x 100%
We know that Sage owns r shares, so we can substitute r for Sage's number of shares:
(r / s) x 100%
Therefore, the percent of shares Sage owns in the Glen Oaks Village Co-op is:
(r / s) x 100%