It doesn’t really matter if the answer you chose is correct or not
The first question he’ll ask is, “How’s Glough and his wife?” If you answer wrong, he’ll attack you. It doesn’t really matter if the answer you chose knight gold is correct or not.
If you kill him, then he’ll drop a Lumber order. Pick it up and return it to the king. If you don’t want to fight the Foreman and to get the three answers right, they are:
Question 1: “How are Glough and his wife?” Answer: “She is no longer with us”
Question 2: “What is Glough’s favorite food?” Answer: “Wormhole”
Question 3: “What is his new girlfriend called?” Answer: “Anita”
Once you have the Lumber order, go back to the entrance of Tree Gnome
Strong-hold (teleport to Ardougne or nearby towns to lessen the distance). If you can’t use any teleportation spells then walk all the up to Brim-haven’s port and talk to the officer to sail you to Ardougne.
From there on, head to Tree Gnome Stronghold. Once you arrive at the entrance, the guards will not let you open the gate. Speak to Femi, who’s nearby.
She’ll sneak you in for free, if, sometime earlier in the game, you’ve helped her carry the crate she asked you to.