Yesterday he did not sleep for $$24 - 20 = 4$$ hours, so he ate $$4 \times 5 = 20$$ grams of leaves. 
When Coco the Caterpillar is not sleeping, he eats $$5$$ grams of leaves per hour. Yesterday he slept $$20$$ hours. How many grams of leaves did he eat yesterday? 
Options:
- $$0$$ 
- $$5$$ 
- $$10$$ 
- $$20$$ 
- $$40$$ 