Answer
Illegible, eggshells and bobsleigh. The longest word is bibliologies with 12 letters.
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Puzzle 14
From each of these words, remove one letter, and then rearrange the remaining letters to find a new word. The resulting ten new words are related to each other.
Reasoning
In 36 hours, Alex could empty 2 lots of bookshelves, Billie could also empty 2 lots of bookshelves, and Drew could refill 1 lot of bookshelves.
So, 2 + 2 − 1 = 3 lots of bookshelves in 36 hours. Which is 12 hours for one lot of bookshelves.
Alternative Reasoning
Alex and Billie can each empty 1/18 of the bookshelves in 1 hour, but Drew will refill 1/36 of the bookshelves in one hour.
So in one hour we have 1/18 + 1/18 − 1/36 = 1/12.
So it would take 12 hours to empty the bookshelves.