The number which exceeds 16% of it by 42 is
Aptitude
Percentage
Difficulty: Easy
Choose an option
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A50
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B52
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C58
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D60
Answer
Correct Answer: 50
Explanation
### Concept & Formula
Every number represents 100% of itself. If a number "exceeds" a percentage of itself by a specific value, that value represents the remaining percentage gap between 100% and the given percentage.
$$ \text{Number} (100\%) - \text{Percentage} (P\%) = \text{Remaining Percentage} ((100-P)\%) $$
### Step-by-Step Solution
* Let the required number be $x$.
* "16% of it" can be written as $0.16x$ or $16\% \text{ of } x$.
* The phrase "exceeds... by 42" means the difference between the number and its 16% is 42.
* Set up the algebraic equation:
$$ x - 16\% \text{ of } x = 42 $$
$$ 100\% \text{ of } x - 16\% \text{ of } x = 42 $$
$$ 84\% \text{ of } x = 42 $$
* Convert the percentage to a fraction to solve:
$$ \frac{84}{100} \times x = 42 $$
* Solve for $x$:
$$ x = 42 \times \frac{100}{84} $$
* Notice that 42 is exactly half of 84.
$$ x = \frac{1}{2} \times 100 = 50 $$
### Exam Strategy & Shortcut
Think entirely in percentages. The number itself is 100%.
It exceeds its 16% by $(100\% - 16\%) = 84\%$.
So, 84% of the value is equal to 42.
Notice the simple math: 42 is exactly half of 84.
If $84\% = 42$, then $100\%$ must be exactly half of 100, which is 50.
### Common Pitfall
The phrasing can be tricky. Students often misread this as "16% of a number is 42" and calculate $x = \frac{42}{0.16}$, or they write $0.16x + 42 = x$ and make an arithmetic error. Translating the English phrase "exceeds... by" directly to a subtraction equation ($A - B = \text{difference}$) prevents this.
### Final Answer
**Therefore, the correct answer is 50.**