Theo đề bài, ta có: p+e+n=36
Vì p=e => 2p+n=36
=> n=36-2p
Lại có: \(p< n\le1,5p\)
<=> \(p< 36-2p< 1,5p\)
<=> \(\left\{{}\begin{matrix}36-2p>p\\36-2p\le1,5p\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}36>3p\\36\le3,5p\end{matrix}\right.\)
<=>\(\left\{{}\begin{matrix}12>p\\10,28\le p\end{matrix}\right.\)<=> \(10,28\le p< 12\)
=> p=e=11
=> n=14