Eve was only tempted because she was the first to meet the serpent. Had adam done so first, it would have been him to first eat the fruit. The moral of the story is that sin is inevitable and that in order for humans to have free will (as god intended), humans would have to eat from the Tree of Knowledge, or in other words, become intelligent enough to actually make decisions.
God is omniscient, so it was never a test. God knew that when he put all the parameters in place Adam would fail. God needed to add sin to the list of imperfections he placed on his imperfect creations. God then passes the sin on to us because of the actions of Adam and Eve in the Garden of Eden. We are therefore guilty of that sin without actually having committed it. Just the way God has foreseen it.
I hate to retract a statement and look stupid myself but i have to do it. If eve could tempt adam to eat from the tree the devil would have easily convinced adam to eat from the tree. The devil is the kind of persuasion and deception. A funny fact though about the bible is that the devil didnt deceive eve. He told her when you eat from the tree you will not surely die for god knows that when you eat of the tree you will be like god knowing right from wrong. And god actually lied because he said you must not eat from the tree for WHEN you eat from it you will surely die. They wouldnt die right then like he said and some translations of the bible say for when you eat from the tree you will die that day. The christian defence is that death means spiritual death. But they added a word that isnt in the book. They are putting words in "gods" mouth saying thats what he meant because if he didnt mean that its proof that gods the liar and the devil tells the truth.
Adam took the apple anyways. I don't agree it was inevitable, but he still ended up doing it, and probably still would've fallen to temptation. Eve never forced him to eat the apple and you can infer from the events in the text that he heard this whole conversation between Eve and the Serpent, seeing that she gave him the fruit right after eating it herself.
Without Eve there is no story and no adam to commit a sin. This is simply a story that helps us understand the human condition and our need to explain where we come from, which as human beings, we come from a father and MOTHER, so in the explanation of where we come from we need both.