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If a+b+c=3,a2+b2+c2=6a+b+c=3, a^{2}+b^{2}+c^{2}=6 and 1a+1b+1c=\frac{1}{a}+\frac{1}{b}+\frac{1}{c}= 1 where a,ba, b and cc are non-zero numbers, then abc=?a b c=?

a

13\frac{1}{3}

b

23\frac{2}{3}

c

32\frac{3}{2}

d

1

Answer : Option C
Explanation :

1a+1b+1c=1\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=1

bc+ca+ababc=1\Rightarrow \frac{b c+c a+a b}{a b c}=1

bc+ac+ab=abc\Rightarrow b c+a c+a b=a b c \ldots (i)

Again, (a+b+c)2=a2+b2+c2+2(ab+bc+ac)(a+b+c)^{2}=a^{2}+b^{2}+c^{2}+2(a b+b c+a c)

(a+b+c)2=a2+b2+c2+2abc\Rightarrow(a+b+c)^{2}=a^{2}+b^{2}+c^{2}+2 a b c

32=6+2abc\Rightarrow 3^{2}=6+2 a b c

9=6+2abc\Rightarrow 9=6+2 a b c

3=2abcabc=32\Rightarrow 3=2 a b c \Rightarrow \mathrm{abc}=\frac{3}{2}

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