diff --git a/ch03-lists-tuples/e09b4_even_odd_sums.py b/ch03-lists-tuples/e09b4_even_odd_sums.py
index 3afc336..fd5d941 100755
--- a/ch03-lists-tuples/e09b4_even_odd_sums.py
+++ b/ch03-lists-tuples/e09b4_even_odd_sums.py
@@ -2,18 +2,11 @@
 """Solution to chapter 3, exercise 9, beyond 4: even_odd_sums"""
 
 
-def even_odd_sums(numbers):
-    """Takes a list of numbers, and returns a two-element
-list containing the sum of the even elements and the
-sum of the odd elements.
-"""
-    evens = []
-    odds = []
+# Write a function that takes a list or tuple of numbers. Return a two-element list,
+# containing (respectively) the sum of the even-indexed numbers and the sum of
+# the odd-indexed numbers. So calling the function as even_odd_sums([10, 20,
+# 30, 40, 50, 60]), you’ll get back [90, 120].
 
-    for one_number in numbers:
-        if one_number % 2:
-            odds.append(one_number)
-        else:
-            evens.append(one_number)
 
-    return [sum(evens), sum(odds)]
+def even_odd_sums(any_type):
+    return [sum(any_type[::2]),sum(any_type[1::2])]