Difficulty: Easy
Correct Answer: 50
Explanation:
Introduction / Context:Translate a verbal statement about a number’s relationship to its own percentage into an algebraic equation. These appear often in profit-loss language and growth problems where a quantity is compared to a fraction of itself and an absolute difference is given.
Given Data / Assumptions:Let N be the number. “Exceeds 20% of itself by 40” means N − 0.20N = 40.
Concept / Approach:Compute the left side: N − 0.20N = 0.80N. Equate to 40 and solve for N by dividing. This yields a quick one-step calculation once properly translated.
Step-by-Step Solution:
N − 0.20N = 40 0.80N = 40 N = 40 / 0.80 = 50Verification / Alternative check:20% of 50 is 10; 50 is 40 more than 10, so the statement holds perfectly.
Why Other Options Are Wrong:60 gives 12 as 20% and the difference would be 48; 80 gives diff 64; 320 gives diff 256; 40 is not consistent with the equation.
Common Pitfalls:Misreading “exceeds … by 40” as a percentage or using the wrong base. Keep distinction between absolute differences and percentage relations clear.
Final Answer:50
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