Solve $14 \times 627 \div \sqrt{1089} = x^3 + 141$
Aptitude
Simplification
Difficulty: Medium
Choose an option
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A$5\sqrt{5}$
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B$(125)^3$
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C25
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D5
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ENone of these
Answer
Correct Answer: 5
Explanation
### Concept & Formula
This problem evaluates operational hierarchy (BODMAS/VBODMAS) along with finding perfect square roots and solving basic cubic equations.
* Square root calculation: $\sqrt{1089} = 33$
### Step-by-Step Solution
* **Step 1:** Find the square root of $1089$:
$$\sqrt{1089} = 33 \quad (\text{since } 30^2 = 900 \text{ and } 40^2 = 1600)$$
* **Step 2:** Substitute back into the equation and apply division first:
$$14 \times (627 \div 33) = x^3 + 141$$
$$627 \div 33 = 19$$
* **Step 3:** Perform the multiplication:
$$14 \times 19 = 266$$
* **Step 4:** Equate and solve for $x^3$:
$$266 = x^3 + 141$$
$$x^3 = 266 - 141 = 125$$
* **Step 5:** Compute the cube root:
$$x = \sqrt[3]{125} = 5$$
### Exam Strategy & Shortcut
**Quick Estimation:**
Knowing basic squares and cubes speeds up this process tremendously. Knowing $\sqrt{1089} = 33$ simplifies $627/33$ to just under $20$ (specifically $19$). $14 \times 19$ is roughly $266$. Subtracting $141$ yields exactly $125$. Recognizing $125$ as a perfect cube ($5^3$) immediately reveals $x = 5$.
### Common Pitfall
* **Wrong Order of Operations:** Executing $14 \times 627$ before dividing by $\sqrt{1089}$ creates massive numbers that are difficult to manage. Always perform division before multiplication according to BODMAS rules.
### Final Answer
**Therefore, the correct answer is 5.**