Shelly's 3 kids spent all day at the water park.  Mitchel went down the water slide 30 times.  Anne went down the slide 30% less than Mitchel and Robert went down 4 times as much as Anne.  How many times did Robert go down the water slide?
Anne went down the slide 30% less than Mitchel who went down 30 times so that's .30*30 = <<30*.01*30=9>>9 times less
Mitchel went down 30 times and Anne went down 9 times less than him for a total of 30-9 = <<30-9=21>>21 times
Robert went down the slide 4 times as much as Anne, who went down 21 times so Robert went down the slide 4*21 = <<4*21=84>>84 times
#### 84