There are no laws about dating. There are laws about sexual contact, so depending on the state, there could be an issue, but not in most of them.
Yes, he can.
1720 is spelled seventeen twenty or seventeen hundred and twenty
Probably not, but the laws vary from state to state and country to country. In most places, the legal age of sexual consent is 16. There are some places where it is 17 or 18.
twenty-six point one seven or twenty-six and seventeen hundredths or in currency twenty-six dollars seventeen cents
17/28 (read like "seventeen over twenty-eight" or "seventeen twenty-eighths"
{| |- | Contact the police. It is battery and is a crime. They will determine if charges can be brought against the 23 year old. |}
85%
.85
46
It is 68%.
That is 85%