On the second day, Mr. and Mrs. Hugo traveled 200 x 3/4 = <<200*3/4=150>>150 miles.
They traveled a total of 200 + 150 = <<200+150=350>>350 miles in the first two days.
On the third day, they traveled 350 x 1/2 = <<350*1/2=175>>175 miles.
So, Mr. and Mrs. Hugo traveled a total of 200 + 150 + 175 = <<200+150+175=525>>525 miles for 3 days.
#### 525