Atriangular pyramid and a triangular prism have congruent bases and the same height the triangular pyramid has a volume of 90m3 what is the volume if the prism?

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.