Problem 1 · 2016 AMC 8
Easy
Arithmetic & Operations
unit-rate
The longest professional tennis match lasted a total of 11 hours and 5 minutes. How many minutes is that?
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Answer: C — 665 minutes.
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Hint 1 of 2
You can't just smush "11" and "5" together — hours and minutes are different-sized units. Convert everything to the SAME unit (minutes) before combining.
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Hint 2 of 2
Each hour is worth 60 minutes, so the hours become 11 × 60; the 5 loose minutes are already in the right unit and just get added on.
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Approach: convert to one common unit, then add
- Rewrite the hours as minutes: 11 hours = 11 × 60 = 660 minutes.
- Add the 5 leftover minutes: 660 + 5 = 665 minutes.
- Sanity check: the answer must be a bit more than 11 × 60 = 660, which rules out 605 and 655 instantly — whenever you convert a big-to-small unit, expect the number to grow.
- You'll see this again as: any "mixed unit" problem (feet + inches, dollars + cents, weeks + days) — pick the smallest unit and convert the rest down to it.
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