Solve this and you're at least 110IQ
In eternal inflation, How can you estimate how many bubble universes exist today, and how close to our universe would a new bubble universe need to form in order for them to collide before inflation moves them too far apart?

Assume that the number of bubble universes forming every second is proportional to the volume of the inflating region, and that inflation proceeds at a minimum rate of a 10^26 increase in the scale factor every 10^-32 seconds

You should be able to solve this.