Fix typo in general RRF calculation, a=chris

diff --git a/en-US/pages/ranking.thtml b/en-US/pages/ranking.thtml
index e4dd424..9741843 100644
--- a/en-US/pages/ranking.thtml
+++ b/en-US/pages/ranking.thtml
@@ -73,7 +73,7 @@ frac{1}{59 + mbox(Rank)_(mbox(Rel))(d)} + frac{1}{59 +
     `mbox(CL)_1, ..., mbox(CL)_n` were the scores from the classifiers being used
     for ranking, then the formula would become:</p>
 <p class="center">
-`mbox(RRF)(d) := 200(frac{1}{59 + mbox(Rank)_(mbox(DR))(d)} +
+`mbox(RRF)(d) := frac{600}{n+3}(frac{1}{59 + mbox(Rank)_(mbox(DR))(d)} +
 frac{1}{59 + mbox(Rank)_(mbox(Rel))(d)} + frac{1}{59 +
     mbox(Rank)_(mbox(Prox))(d)} +
     sum_{i=1}^nfrac{1}{59 + mbox(Rank)_(mbox(CL)_i)(d)}).`