Are there exactly 4 distinct keys that are working on the old typewriter?
1. An old typewriter is defective in such a way that its blank key is not functioning, and the typewriter allows only 4 letters per word by forcing a space character to be inserted after each four-letter word. A monkey sitting at the typewriter is aware of this peculiarity and presses only distinct keys for each four-letter sequence. Some keys of this typewriter are not functioning.
2. A monkey is able to create only 24 distinct four-letter words.