Verizon has a cell phone plan for $28.00 per month plus $.30 per minute with unlimited anytime network minutes and a free flip phone for new customers. How do I put this in an equation. Sprint has a plan for $30.00 per month plus $.029 per minute unlimited minutes on weekend, but you must purchase a $70.00 phone with a $40.00 rebate and sign up for a 2 year contract.

Question

Verizon has a cell phone plan for $28.00 per month plus $.30 per minute with unlimited anytime network minutes and a free flip phone for new customers. How do I put this in an equation. Sprint has a plan for $30.00 per month plus $.029 per minute unlimited minutes on weekend, but you must purchase a $70.00 phone with a $40.00 rebate and sign up for a 2 year contract.
 
Which one of these plans is a better deal?

Steve · Answer

Since Sprint requires a 2-year (24-month) contract, for M months and m non-weekend minutes per month, that is

(70-30) + 24(30+.029m) = 760 + .696m

Verizon for 24 months with m non-network minutes minutes each, charges

24(28+.3m) = 672 + 7.2m

All that stuff about weekend minutes, non-network minutes throws everything off, but with equal numbers of charged minutes, Verizon is a better 2-year deal only if

672 + 7.2m < 760 + .696m
m < 13.5