Problem 5 · 1994 AJHSME
Easy
Ratios, Rates & Proportions
unit-conversion
Given that 1 mile = 8 furlongs and 1 furlong = 40 rods, the number of rods in one mile is
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Answer: B — 320.
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Hint 1 of 2
The miles–rods jump is too big to do directly, but you have a stepping-stone (furlongs) that connects them — hop mile → furlong → rod.
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Hint 2 of 2
Each hop multiplies: stack the two conversion factors together. (Ignore the decoy numbers 660, 1760, 5280 — those are real mile facts but for feet/yards, not this puzzle's furlongs and rods.)
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Approach: chain the conversions
- Bridge through furlongs: 1 mile is 8 furlongs, and each of those 8 furlongs is 40 rods.
- So 1 mile = 8 × 40 = 320 rods.
- Why multiply (not add): each furlong unpacks into 40 rods, and you have 8 furlongs, so it's 8 groups of 40 — that's multiplication. This 'chain the units' move handles any multi-step conversion.
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