ABC26GN0778 · Decimal Fractions
Subject: General Aptitude · Chapter: Decimal Fractions · Exam: 2005 · Marks: · Difficulty:
The value of $\frac{5.71 \times 5.71 \times 5.71-2.79 \times 2.79 \times 2.79}{5.71 \times 5.71+5.71 \times 2.79+2.79 \times 2.79}$ is
(a)2.82
(b)2.92
(c)8.5
(d)8.6
Answer
Explanation
Given expression $=\frac{(5.71)^{3}-(2.79)^{3}}{(5.71)^{2}+5.71 \times 2.97+(2.79)^{2}}$ $$\begin{aligned} & =\left(\frac{a^{3}-b^{3}}{a^{2}+a b+b^{2}}\right) \\ & =(a-b)=(5.71-2.79)=2.92 . \end{aligned}$$
Explanation as extracted from the printed page; notation may be imperfect.
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