Riddle: A bird has a head 9cm long. The tail is equal to the size of the head plus a half of the size of the body. The body is the size of the head plus the tail.
How long is the bird?
: 72cm. Th head is 9cm. The tail is 18 + 9= 27cm. The body is 9 + 18 + 9= 36cm. 9 + 27 + 36= 72cm.