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A pay phone service charges Php 5 for the first three minutes and Php 1 for every minute additional or afraction thereof. How much will a caller have to pay if his call lasts for 8 minutes? Write a rule that best describes the problem and draw its graph using any method.​

User NickOS
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Final answer:

The total cost of an 8-minute call is Php 10. A rule describing the pricing is C(x) = 5 if x ≤ 3, and C(x) = 5 + (x - 3) if x > 3. The graph shows a flat line at Php 5 up to 3 minutes, then a straight line increasing by Php 1 per minute after that.

Step-by-step explanation:

To determine how much a caller would have to pay for an 8-minute call with the given pricing scheme, we must first consider the initial charge of Php 5 for the first three minutes. Then, we account for the additional minutes beyond the first three. Since the call lasts for 8 minutes, there are 5 additional minutes at a rate of Php 1 per minute or fraction thereof.

The cost for the additional 5 minutes is Php 1 x 5 = Php 5. Therefore, the total cost of the call is Php 5 (initial charge) + Php 5 (additional minutes) = Php 10.

To create a rule that describes the problem, let x represent the total minutes of the call and C(x) represent the total cost. Then the rule can be expressed as:

  • C(x) = 5, if x ≤ 3
  • C(x) = 5 + (x - 3), if x > 3

To graph this, you plot two sections. From x=0 to x=3, the cost is constant at Php 5. For x>3, the cost increases by Php 1 for each additional minute.

User MurielK
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