If $$\frac{11-13x}{x}+\frac{11-13y}{y}+\frac{11-13z}{z}=5$$, then what is value of $$\frac{1}{x}+\frac{1}{y}+\frac{1}{z}$$ ?
Given : $$\frac{11-13x}{x}+\frac{11-13y}{y}+\frac{11-13z}{z}=5$$
Let $$\frac{11-13x}{x}=\frac{11-13y}{y}=\frac{11-13z}{z}=k$$
=> $$k+k+k=5$$
=> $$k=\frac{5}{3}$$
=> $$\frac{11-13x}{x}=\frac{5}{3}$$
=> $$33-39x=5x$$
=> $$39x+5x=44x=33$$
=> $$x=\frac{33}{44}=\frac{3}{4}$$ -------(i)
Similarly, $$y=z=\frac{3}{4}$$ --------(ii)
To find : $$\frac{1}{x}+\frac{1}{y}+\frac{1}{z}$$
= $$\frac{4}{3}+\frac{4}{3}+\frac{4}{3}$$
= $$\frac{12}{3}=4$$
=> Ans - (D)
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