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Let $p$ and $q$ be prime divisors of finite group $G$. Also let $n_{p}$ be the number of Sylow $p$-subgroups of $G$ . Is there any example such that $n_{p}=n_{q}\neq 1$? Thanks in advance.

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There are $33$ such groups of order less than $256$. –  Tom De Medts Jul 6 '12 at 16:08
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This is hardly a research level question! –  Derek Holt Jul 6 '12 at 16:35
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Consider any Frobenius group with nilpotent complement not of prime power order. There are many such groups. –  Geoff Robinson Jul 6 '12 at 16:42
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up vote 4 down vote accepted

Unless I mis-computed, this happens in the group of affine transformations ($x \mapsto ax+b$ with $a\neq 0$) over the field of 7 elements. There seem to be 7 2-Sylow subgroups and 7 3-Sylow subgroups.

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This is true in groups of affine transformations mod a a prime $l$ more generally, for $p$ and $q$ any two prime divisors of $l-1$. The stabilizer of a $p$ or $q$-Sylow subgroup is the stabilizer of the unique point it fixes. –  Will Sawin Jul 6 '12 at 16:33
    
@Andreas Blass: Thank you so much! –  T.Rezy Jul 6 '12 at 18:26
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