Difficulty: Hard
Correct Answer: 1660
Explanation:
Introduction / Context:
This question tests approximation by rounding to nearby convenient integers and using basic square/cube values. The given decimals are extremely close to 8, 13, and 4, so the inner expression can be estimated quickly and then squared to get a final approximation.
Given Data / Assumptions:
Concept / Approach:
Approximate each component using nearby integers:
(7.99)^2 ≈ 8^2 = 64
(13.001)^2 ≈ 13^2 = 169
(4.01)^3 ≈ 4^3 = 64
Then combine: 64 − 169 + 64 ≈ −41, and square it: (−41)^2 = 1681. The closest listed value to 1681 is 1660.
Step-by-Step Solution:
1) Round terms:
7.99 ≈ 8, 13.001 ≈ 13, 4.01 ≈ 4
2) Compute approximate powers:
8^2 = 64, 13^2 = 169, 4^3 = 64
3) Combine inside brackets:
64 − 169 + 64 = 128 − 169 = −41
4) Square the result:
(−41)^2 = 1681
5) Compare to options: 1660 is the nearest to 1681.
Verification / Alternative check:
Since the final expression is a square, it must be non-negative. That immediately eliminates negative options like −1660 and −1800. Also, the rounded estimate 1681 is much closer to 1660 than 1450 or 1800, so 1660 is the best approximation.
Why Other Options Are Wrong:
• Negative values: impossible because the entire expression is squared.
• 1450: too far below 1681.
• 1800: farther away than 1660.
Common Pitfalls:
• Forgetting the outer square and choosing a negative option.
• Rounding 13.001 to 14 by mistake (wrong nearest integer).
Final Answer:
1660
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