Why are prayers repeated in the rosary?

I think it 3 times. Dont know, cheack on a other wbsite to see if it is true

Roman Catholic AnswerThe Hail Mary is repeated, three times at the beginning of the rosary as one is praying for the virtues of faith, hope, and charity. Within each decade, the Hail Mary is repeated ten times. My spiritual director once told me that this was to be "like the background music" to one's meditation". In other Words, the heart of the rosary is the meditation we do on each mystery, and the Words of the Hail Mary are the background or framework on which we "hang" our meditation, if you will. Please note that Christian meditation has absolutely nothing whatsoever in common with Eastern meditation. Christian meditation is beginning prayer, in which we are praying to God through thinking about a particular mystery or event and offering it to God, while applying it's lessons in our life, and asking God for the grace and strength to live in conformity with His will for us as expressed by whatever we are meditating about.