1.

The HCF and LCM of the two numbers x and y are respectively 7 and 42. If x + y = 35, then \(\frac{1}{x} + \frac{1}{y}\) is equal to :1). 6/352). 5/423). 3/424). 1/42

Answer»

$(\frac{1}{X} + \frac{1}{y} = \frac{{x + y}}{{xy}} = \frac{{35}}{{xy}})$

Using the known identity: product of TWO NOS. = LCM × HCF,

we have:

xy = 7 × 42

$(\Rightarrow \frac{1}{x} + \frac{1}{y} = \frac{{35}}{{7 \TIMES 42}} = \frac{5}{{42}})$


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