Q. The average of x numbers is y and average of y numbers is x. Then the average of all the numbers taken together is:
Answer: $latex \frac{2xy}{x+y}&s=1$
Notes: Sum of x numbers = xy Sum of y numbers = xy ∴ Required Average $latex = \frac{xy+xy}{x+y} = \frac{2xy}{x+y}&s=1$ Hence option [D] is the right answer

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