More Questions from Problems on Numbers

What is the greater of the two numbers whose product is 1092 and the sum of the two numbers exceeds their difference by 42?

Aptitude Problems on Numbers Difficulty: Medium
Choose an option
  • A
    44
  • B
    48
  • C
    52
  • D
    54
  • E
    None of these

Answer

Correct Answer: 52

Explanation

## Concept & Logic Translating a word problem into algebraic expressions is key here. The phrase "sum exceeds difference by" can be translated into a direct equation. Interestingly, the variables representing the "greater" number will cancel out in this translation, instantly revealing the smaller number. $$ (x + y) - (x - y) = \text{Excess Amount} $$ ## Step-by-Step Solution * **Given:** Let the two numbers be $x$ and $y$, where $x > y$. The product $x \times y = 1092$. * **Calculation / Deduction:** * The sum is $(x + y)$. The difference is $(x - y)$. * Set up the equation based on the condition "sum exceeds difference by 42": * $(x + y) - (x - y) = 42$ * Simplify the left side: * $x + y - x + y = 42$ * $2y = 42$ * $y = 21$ * We now know the smaller number is $21$. Use the product to find the greater number ($x$): * $x \times 21 = 1092$ * $x = \frac{1092}{21}$ * $x = 52$ ## Exam Strategy & Shortcut **Logical Deduction:** Realize that the difference between the sum $(A+B)$ and the difference $(A-B)$ of two numbers is ALWAYS simply twice the smaller number ($2B$). Therefore, if the difference is $42$, the smaller number is instantly $21$. Divide $1092$ by $21$ to get $52$. To quickly divide $1092$ by $21$, look at the unit digit: $1 \times \text{what} = 2$? It must end in $2$. Look at the options; $52$ is the only logical choice that works ($20 \times 50 = 1000$). ## Common Pitfall A major pitfall is trying to set up complex quadratic equations using substitution before simplifying the "sum exceeds difference" clause. Always simplify your linear conditions completely before plugging them into a product condition. ## Final Answer **Therefore, the correct answer is 52.**
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