ABC26GN1347 · Square Roots and Cube Roots

Subject: General Aptitude · Chapter: Square Roots and Cube Roots · Exam: · Marks: · Difficulty:

If $y=5$, then what is the value of $10 y \sqrt{y^{3}-y^{2}}$ ?
(a)$50 \sqrt{2}$
(b)100
(c)$200 \sqrt{5}$
(d)500
Answer
Answer (as printed): D
Explanation
$$\begin{aligned} 10 y \sqrt{y^{3}-y^{2}} & =10 \times 5 \sqrt{5^{3}-5^{2}} \\ & =50 \times \sqrt{125-25}=50 \times \sqrt{100} \\ & =50 \times 10=500 \end{aligned}$$

Explanation as extracted from the printed page; notation may be imperfect.

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