Difficulty: Easy
Correct Answer: 1/2
Explanation:
Introduction / Context:
Many repeating decimals correspond to simple fractions. Recognizing 0.142857 and 0.285714 as classic recurring forms linked to sevenths makes the division straightforward without long computation.
Given Data / Assumptions:
Concept / Approach:
Division of fractions a/b ÷ c/d equals (a/b) * (d/c). Here, (1/7) ÷ (2/7) = (1/7) * (7/2) = 1/2. Identifying the recurring-decimal–fraction mapping saves time.
Step-by-Step Solution:
0.142857 = 1/7; 0.285714 = 2/7.Compute the quotient: (1/7) ÷ (2/7) = (1/7) * (7/2) = 1/2.
Verification / Alternative check:
Decimal check: 0.142857 ÷ 0.285714 ≈ 0.5. Since both are precise recurring forms of sevenths, the exact result is 1/2.
Why Other Options Are Wrong:
1/3 and 2 do not match the straightforward fraction division; 10 is much too large; 3/2 inverts the intended ratio.
Common Pitfalls:
Forgetting that both decimals are exact fractional forms of sevenths, leading to unnecessary long division.
Final Answer:
1/2
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