Let $G$ be a group of order 24, and we shall assume there there exist a non-normal 2-sylow group in $G$. i want to show that it's not simple.
first i have showed that there are exactly three 2-sylow group's.
and now i am trying to show that there is a non trivial homomorphism from $G$ to $S_3$. i know that $S_3\cong D_3$ and indeed there are three 2-sylow groups in $D_3$ , the reflection's. and there is one $3-$sylow group in $D_3$ so i wanted to creat a homomorphism that take the different p-sylow groups in $G$ and set them in right $p-$sylow group's in $D_3$ but for that i need to show that the intersection of every two $2-$sylow gouts in $G$ is trivial. and i can't manage to do that....
A simple group $G$ of order $24$ would have three Sylow $2$-subgroups, and so there would be a non-trivial homomorphism from $G$ to $S_3$ (see the comment) which will be injective by simplicity and therefore $24$ would divide $6$ which is absurd.