ABC26GN0758 · Decimal Fractions

Subject: General Aptitude · Chapter: Decimal Fractions · Exam: · Marks: · Difficulty:

The value of $(1.25)^{3}-2.25(1.25)^{2}+3.75(0.75)^{2}-$ $(0.75)^{3}$ is

(a)1

(b)$\frac{1}{2}$

(c)$\frac{1}{4}$

(d)$\frac{1}{8}$

Answer

Answer (as printed): D

Explanation

Given expression $= (1.25)^3 - (0.75)^3 - 3(1.25)^2(0.75) + 3(1.25)(0.75)^2 = (1.25-0.75)^3 = (0.5)^3 = \frac{1}{8}$. [∵ $(a-b)^3 = a^3-b^3-3a^2b+3ab^2$]

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

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