Answer:
Vishal can blow ballons at the fastest rate.
Explanation:
Assuming that all balloons are blown to the same size, who can blow balloons at the fastest rate?
To find who can blow ballons at the fastest rate, we divide the number of ballons blown by the number of minutes, and whoever has the highest ratio of ballons blown per minute can blow balloons at the fastest rate.
Ethan can blow 15 balloons in 20 minutes
15/20 = 0.75 ballons per minute
Jun Wei can blow 18 balloons in 25 minutes
18/25 = 0.72 ballons per minute
Vishal can blow 16 balloons in 21 minutes.
16/21 = 0.76 ballons per minute
Since he has the highest rate, Vishal can blow ballons at the fastest rate.