Answer: Salt is a quarter of water, and salt accounts for a fifth of salt water.
6. The carpenter used a piece of wood to make the next paragraph at a time. He used it four times to divide a piece of wood into small pieces with the same length. How much does two small pieces of wood account for this piece of wood?
Answer: Four times * * * sawed five sections, so two small pieces of wood accounted for two-fifths of this piece of wood?