If \(1 + 1/2 + 1/3 + .... + 1/100 = A/B\) where gcd(A,B) = 1 then show that \(AB\) isn't divisible by 5
2 years ago
That's an interesting question. What have you tried? Is it obvious that A is not divisible by 5? Is it obvious that B is not divisible by 5?
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sir, I am still trying
oh i failed to try it