Which of the following functions represent exponential growth

Iknow its nothing to do with education, but what type of thing should i wrote here? ? : ) its for mcdonald's btw.

One cell phone plan charges $20 per month plus $0.15 per minute used. a second cell phone plan charges $35 per month plus $0.10 per minute used. write and solve an equation to find the number of minutes you must talk to have the same cost for both calling plans.

Identify the number as a regional or irrational.explain. 291.87