I got 6. I think I did better on this than the Justin Beiber quiz. Though when the answers were revealed I realized I knew a couple others that I had missed.
According to Wikipedia /en.wikipedia.org/wiki/Miley_Cyrus>, Miley Cyrus and Liam Hemsworth were married in 2018 and divorced in 2020. Please consider amending the question asking for the name of her ex-fiancé to ask for the name of her ex-husband.