Question

which of the following does not belong?

a setback, fireplace, backfire
b homestead, faster, steadfast
c alight, erstwhile, lighter
d terrain, bowtie, rainbow
e fountain, laundry, foundry

Explanation:

Analyze the word patterns in each option

• Option A: "setback", "fireplace", "backfire"
• "setback" and "backfire" share the word "back".
• "fireplace" and "backfire" share the word "fire".
• This forms a chain: setback -> back -> backfire -> fire -> fireplace.

• Option B: "homestead", "faster", "steadfast"
• "homestead" and "steadfast" share the word "stead".
• "faster" and "steadfast" share the word "fast".
• This forms a chain: homestead -> stead -> steadfast -> fast -> faster.

• Option C: "alight", "erstwhile", "lighter"
• "alight" and "lighter" share the word "light".
• "erstwhile" and "lighter" share the word "er" (or "erstwhile" and "alight" do not have a clear compound word overlap like the others). Let's re-examine: "erstwhile" contains "while" and "erst". "lighter" contains "light" and "er". "alight" contains "a" and "light". There is no overlapping compound word chain linking all three.

• Option D: "terrain", "bowtie", "rainbow"
• "terrain" and "rainbow" share the word "rain".
• "bowtie" and "rainbow" share the word "bow".
• This forms a chain: terrain -> rain -> rainbow -> bow -> bowtie.

• Option E: "fountain", "laundry", "foundry"
• "fountain", "laundry", "foundry" do not form compound word chains, but let's look at anagrams or letter patterns.
• Let's look at the compound word pattern again:
• A: set-back, fire-place, back-fire (back + fire = backfire)
• B: home-stead, fast-er, stead-fast (stead + fast = steadfast)
• D: ter-rain, bow-tie, rain-bow (rain + bow = rainbow)
• E: fount-ain, laund-ry, found-ry. No compound word overlap.
• C: a-light, erst-while, light-er. No compound word overlap.
• Let's look at a different pattern: overlapping letters/substrings.
• A: setback, fireplace, backfire -> "back" is in setback and backfire; "fire" is in fireplace and backfire.
• B: homestead, faster, steadfast -> "stead" is in homestead and steadfast; "fast" is in faster and steadfast.
• D: terrain, bowtie, rainbow -> "rain" is in terrain and rainbow; "bow" is in bowtie and rainbow.
• E: fountain, laundry, foundry -> "found" is in fountain (fount) and foundry (found), "dry" is in laundry and foundry. Specifically, "foundry" is made of "found" (from fountain/fount) and "ry" (from laundry).
• C: alight, erstwhile, lighter -> "light" is in alight and lighter. "erstwhile" has no overlapping morphemes or significant substrings with the other two words.

Identify the odd one out

• Options A, B, D, and E all consist of triplets where one word is a combination of parts of the other two words (either compound words or overlapping letter segments).
• Option C does not follow this pattern because "erstwhile" does not share parts with "alight" or "lighter".

Answer:

• (A) setback, fireplace, backfire
• (B) homestead, faster, steadfast
• (C) alight, erstwhile, lighter (Correct answer)
• (D) terrain, bowtie, rainbow
• (E) fountain, laundry, foundry