Mary spent 100/4= <<100/4=25>>25 dollars on a new video game.
So, after the video game purchase, Mary was left with 100 - 25 = <<100-25=75>>75 dollars.
Mary then bought swimming goggles for 75/5 = <<75/5=15>>15 dollars
Mary had 75 - 15 = <<75-15=60>>60 dollars left
#### 60