genitive VS compound noun

0Dear teachers,02br
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00First, happy New Year to you all, and thank you for your kindness and dedication. I want to tell you that you've helped a lot throughout these years and I feel deeply endebted to you.02br
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00My question for today is: Can I use the indefinite article with the genitive? Is it correct to say: "It's 01b00A02b00 five kilometres01b00'02b00 walk" ?02br
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00What's the difference between : "It's 01b00a02b00 five kilometres01b01font00'02font00 02b00walk" (genitive); and 02br
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00"It's 01b00a02b00 five01b01font00-02font02b00kilometre walk" (compound noun) ?02br
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00What should I say: 02br
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00a) "There is two weeks delay" ; (with or without an apostrophe after "weeks" ?) 02br
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00b) "There is 01b00a02b00 two weeks delay" ; (with or without an apostrophe after "weeks" ?) 02br
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00c) "There is a two-week delay" ?02br
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00Many thanks,02br
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00Hela0-