The difference between a text without problems and a text with problems is like the difference between learning to read a language and learning to speak it.
Disturbing the Universe
Tree and Vine
A tree is 20 feet tall and has a circumference of 3 feet. There is a vine that winds seven equally spaced times around the tree and reaches the top. What is the length of the vine? (China 100 BCE)Click here to reveal the answer