Question

Evaluate:
$\frac{{\left(0.43\right)}^3+{\left(1.47\right)}^3+{\left(1.1\right)}^3-3\times 0.43\times 1.47\times 1.1}{{\left(0.43\right)}^2+{\left(1.47\right)}^2+{\left(1.1\right)}^2-0.43\times 1.43-0.43\times 1.1-1.47\times 1.1}$

• A. $1.90$
• B. $2.87$
• C. $3$
• D. $3.47$

Answer 1

The correct option is C $3$

Reqd. exp. is of type
$\frac{a^3+b^3+c^3-3abc}{a^2+b^2+c^2-ab-bc-ca}$
You know that
$(a+b+c)(a^2+b^2+c^2-ab-bc-ca)=a^3+b^3+c^3-3abc$
$\Rightarrow a+b+c=\frac{a^3+b^3+c^3-3abc}{a^2+b^2+c^2-ab-bc-ca}$
$\therefore$ Reqd.exp.$=0.43+1.47+1.1=3$