Word Ladder: Hall to Silk
Read the puzzle
A word ladder climbs from HALL at the bottom to SILK at the top, changing one letter at each step: HALL, HILL, ?, MILK, SILK. Which word fills the gap: MILE, MILL, HILT or MALL?
Which word fills the gap?
It must differ by one letter from HILL and from MILK.
MILL
HILL to MILL changes H to M; MILL to MILK changes L to K.
How to solve it
Step one: the missing word must be one letter away from HILL, below it, and one letter away from MILK, above it.
Step two: compare HILL and MILK letter by letter. H against M differs, I and the first L match, and the final L against K differs. Two letters change, so the gap word must change exactly one of them.
Step three: try both orders. Changing the first letter gives MILL, a real word. Changing the last letter gives HILK, which is not. So the gap is MILL: HILL to MILL swaps H for M, and MILL to MILK swaps L for K.
Check the other choices. HILT is one step from HILL, but two from MILK, since both the H and the T differ. MILE is one step from MILK but two from HILL, since both the H and the final L change. MALL is two steps from HILL, because both the H and the I change.
The usual wrong answer is HILT, because it looks so close to HILL. It only satisfies one neighbour. A quick check for any ladder: write the gap word between its neighbours and make sure exactly one letter differs on each side.


