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25 votes
25 votes
Find four fractions between 1/10 and 1/8

User IanWatson
by
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1 Answer

16 votes
16 votes

9514 1404 393

Answer:

5/48, 5/46, 5/44, 5/42

Explanation:

We can choose unit fractions with denominators between 8 and 10, separated by (10-8)/5 = 0.4 units:

1/8.4 = 5/42

1/8.8 = 5/44

1/9.2 = 5/46

1/9.6 = 5/48

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Check

  • 1/8 = 0.125
  • 5/42 ≈ 0.119
  • 5/44 ≈ 0.114
  • 5/46 ≈ 0.109
  • 5/48 ≈ 0.104
  • 1/10 = 0.100

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Additional comment

There are an infinite number of such fractions. We are given unit fractions with different denominators, so it works reasonably well to choose denominators between those given. Then the trick is to convert the fraction to a ratio of integers. In this case, multiplying by (5/5) does the trick.

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Another approach is to write the fractions with a common denominator, then choose numerators between the ones given. For example, 1/10 = 4/40, and 1/8 = 5/40, so you could write some fractions with numerators between 4 and 5. Possibilities are 4.1/40 = 41/400, 4.3/40 = 43/400, 4.7/40 = 47/400, 4.9/40 = 49/400.

User Will Gordon
by
3.0k points