Answer:
1.Judaism, Christianity and Islam are indeed a monotheistic religions for a fact that these three has only one God.These three also largely influenced the world today since they has the highest population, most especially the Christianity and Islam religion.
2.There similarities is that,as I said, they are a monotheistic religion.With regards to origin, they believe in Abraham.They also have in common in morality as stated in their respective scriptures.Moreover, they also share common belief in destiny wherein God will come,clean the world and judge the living and the dead.They also share similarities in views.Lastly, these three definitely believe that Men are higher than Women.