Find the value of \(\rm \frac{1.2\times 1.2\times 1.2-0.2\times 0.2\times 0.2}{1.2\times 1.2+1.2\times 0.2+0.2\times 0.2}\)

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TNPSC Group 1 Services Prelims 2015 Official Paper

Answer 1

Given:

Find the value of \(\rm \frac{1.2\times 1.2\times 1.2-0.2\times 0.2\times 0.2}{1.2\times 1.2+1.2\times 0.2+0.2\times 0.2}\)

Formula used:

(a³ - b³) / (a² + ab + b²) = a - b

Where, a = 1.2 and b = 0.2

Calculations:

(1.2 × 1.2 × 1.2 - 0.2 × 0.2 × 0.2) / (1.2 × 1.2 + 1.2 × 0.2 + 0.2 × 0.2)

⇒ (1.2³ - 0.2³) / (1.2² + 1.2 × 0.2 + 0.2²)

⇒ (1.2 - 0.2)

⇒ 1

∴ The correct answer is option 2.

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