Fraction chain simplification: Compute (3/5) of (4/7) of (7/9) of 425 using cancellation for speed.

Difficulty: Easy

Correct Answer: 113

Explanation:


Introduction / Context:
Successive fractions can often be simplified by cancellation before multiplying. Here, the factor 7 appears in both a numerator and a denominator, making the product much simpler and enabling quick mental calculation with minimal risk of error.


Given Data / Assumptions:

  • Expression: (3/5) * (4/7) * (7/9) * 425
  • All numbers are exact; a neat cancellation exists.


Concept / Approach:
Cancel the 7 in (4/7) with the 7 in (7/9), leaving (3/5) * (4/9) * 425. Multiply constants first or simplify with 425 to avoid large intermediate numbers.


Step-by-Step Solution:

After canceling 7: (3/5) * (4/9) * 425Combine fractions: 12/45 = 4/15Compute 425 * (4/15) = (425/15) * 4425/15 = 28.333..., so product ≈ 113.333...Nearest integer option is 113


Verification / Alternative check:
Exact fraction: 425 * 12/45 = 425 * 4/15 = 1700/15 = 340/3 ≈ 113.333..., confirming 113 as the correct nearest integer option.


Why Other Options Are Wrong:

  • 110, 118, 115, 121: all differ from 113.33; 113 is the integer part of the exact value.


Common Pitfalls:
Multiplying all numerators first and all denominators next without simplifying can lead to bulky numbers and errors. Cancel early to stay accurate.


Final Answer:
113

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