Question 18
Coco is making a hanging mobile from coathangers. Starting with 1 coathanger in the first layer, she hangs 2 coathangers in the second layer, 1 at each end of the first, as shown. She works along each layer following the same pattern, so that every coathanger has 2 new coathangers hanging from it. Coco stops when she has finished 6 layers. How many coathangers are in her mobile?
