diff --git a/app/models/proxy_exercise.rb b/app/models/proxy_exercise.rb
index 699d91f5..2e2216ed 100644
--- a/app/models/proxy_exercise.rb
+++ b/app/models/proxy_exercise.rb
@@ -240,7 +240,7 @@ class ProxyExercise < ApplicationRecord
 
   def tag_diminishing_return_function(count_tag, total_count_tag)
     total_count_tag += 1 # bonus exercise comes on top
-    1 / (1 + (Math::E**(-3 / (0.5 * total_count_tag) * (count_tag - (0.5 * total_count_tag)))))
+    1 / ((Math::E**(-3 / (total_count_tag * 0.5) * (count_tag - (total_count_tag * 0.5)))) + 1)
   end
 
   def select_easiest_exercise(exercises)
diff --git a/lib/py_lint_adapter.rb b/lib/py_lint_adapter.rb
index 42f82b2e..1c742c56 100644
--- a/lib/py_lint_adapter.rb
+++ b/lib/py_lint_adapter.rb
@@ -16,7 +16,7 @@ class PyLintAdapter < TestingFrameworkAdapter
     else
       captures = regex_match.map(&:to_f)
       count = captures.second
-      passed = captures.first >= 0 ? captures.first : 0
+      passed = [captures.first, 0].max
       failed = count - passed
     end