A fast-food restaurant uses a conveyor belt to send the burgers through a grilling machine. If the grilling machine is 1.1 $\mathrm{m}$ long and the burgers require 2.5 $\mathrm{min}$ to cook, how fast must the conveyor belt travel? If the burgers are spaced 15 $\mathrm{cm}$ apart, what is the rate of burger production (in burgers/min)?