$3\mathrm{.}19$ A stream of air at $25C$ and $1$atm is laden with particulate mat$-$

ter $($unit density spheres$)$ of only two sizes: $1m$ and $5m.$ The

stream flows through a pipe at an average velocity of $20\frac{m}{s}.$ The

pipe exhausts into a water mist scrubber where the water drop$-$

lets average $100m$ in diameter. Based only on a comparison of

their impaction numbers, what will be the ratio of particles col$-$

lected to $1m?$