MHB How to find equation from given data?

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The discussion addresses how to derive cost equations for two mobile phone pricing plans. For Plan A, the cost equation is C = 15 + (0.25)t, where C is the total cost in dollars and t is the call time in minutes. For Plan B, the equation is C = 100 + (0.14)t. The calculations involve converting call rates from cents to dollars by dividing by 100. The thread concludes with appreciation for the provided solutions.
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Dear friends,

I am unable to solve the following problem. Will appreciate your help here. Thanks in advance.

The Purple Mobile Phone Company offers the following two pricing plans to customers. Plan A costs \$15/month, with calls at 25c/minute, while Plan B costs \$100/month with calls at 14c/minute. Find an equation that gives C, the cost in dollars, in terms of t, the call time in minutes per month for each plan.
 
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tantrik said:
Dear friends,

I am unable to solve the following problem. Will appreciate your help here. Thanks in advance.

The Purple Mobile Phone Company offers the following two pricing plans to customers. Plan A costs \$15/month, with calls at 25c/minute, while Plan B costs \$100/month with calls at 14c/minute. Find an equation that gives C, the cost in dollars, in terms of t, the call time in minutes per month for each plan.
You are given t in minutes and want to get C in dollars. There is a "cents/minute" so multiplying by t in minutes will result in cents. Dividing that by 100 cents/dollar will put it into dollars. The monthly cost is already in dollars so you can just add that:
C= 15+ (25/100)t

C= 100+ (14/100)t.
 
HallsofIvy said:
You are given t in minutes and want to get C in dollars. There is a "cents/minute" so multiplying by t in minutes will result in cents. Dividing that by 100 cents/dollar will put it into dollars. The monthly cost is already in dollars so you can just add that:
C= 15+ (25/100)t

C= 100+ (14/100)t.

Thanks for your explanation and working for the problem.
 
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