200 Miles (322 km) in 24 Hrs....on a Beach Cruiser???

I am a 44 year old dad who doesn't work out and hasn't road a bike in years. I don't have a nice bike. I own a steel frame beach cruiser with 3 gears. But I want to know if I can ride 200 miles in 24 hrs. So I am going to try and test and train and plan a 210 mile journey across the C&O Canal Trail and the Mount Vernon Trail to take me through one of the most amazing bike trails in the US. We'll see what happens.