A Bad Muffin
A bad muffin likes to eat bad bad ponies. There are 64 ponies and the bad muffin eats 5 every day. After 3 days a bad bad muffin joins the bad muffin and eats 8 ponies every day. After 3 days a bad bad bad muffin joins the two muffins and eats 11 ponies a day. How long (in whole days) does it take for the three muffins to eat the ponies if 20 ponies are reborn every day?