basic cellphone plan cost $20 per month for 60 calling minutes. Additional time costs .40 per minute. The formula gives the monthly cost for this plan C, for x calling minutes, where x 60. How many calling minutes are possible for a monthly cost of at least $28 and at most $40?

Question

basic cellphone plan cost $20 per month for 60 calling minutes. Additional time costs .40 per minute. The formula gives the monthly cost for this plan C, for x calling minutes, where x > 60. How many calling minutes are possible for a monthly cost of at least $28 and at most $40?

PsyDAG · Answer

20 + .40(x-60) = C Insert cost and solve for minutes(x).

khadijah · Answer

A basic cellphone plan costs $20 per month for 60 calling minutes. Additional time costs $0.40 per minute. The formula 𝐶 = 20+0.40 (𝑥 −60) gives the monthly cost for this plan, C, for 𝑥 calling minutes, where 𝑥 > 60. How many calling minutes are possible for a monthly cost of at least $28 and at most $40?