Add exercise

Exercise 3/11 - Doble lokker/11b.py

@@ -0,0 +1,14 @@
+def numberPyramid(length):
+  for i in range(length):
+    print('X', ' ' * i + 'X')
+
+
+def numberPyramidDoubleLoop(length):
+  for i in range(length):
+    space = ''.join([' ' for _ in range(i)])
+    print('X', space + 'X')
+
+
+if __name__ == "__main__":
+  n = int(input('n: '))
+  numberPyramidDoubleLoop(n)