8. At TelePower Plus, long-distance phone calls to China cost $0.59 for the first minute and $0.25 for each additional minute, plus an additional roaming charge of $2.50. If the total charge of a call to Beijing was $11.84, how many minutes did the call last? (Points : 2)
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To solve this problem, we need to set up an equation based on the given information. Let's call the number of additional minutes x.
The cost of the first minute is $0.59, and the cost of each additional minute is $0.25. So, the total cost of the additional minutes is 0.25 * x.
The total cost of the call is the sum of the cost of the first minute, the cost of the additional minutes, and the roaming charge. Therefore, the equation is:
0.59 + 0.25x + 2.50 = 11.84
Now, we can solve the equation to find the value of x, which will represent the number of additional minutes.
First, we need to subtract 0.59 and 2.50 from both sides of the equation:
0.25x = 11.84 - 2.50 - 0.59
Simplifying:
0.25x = 8.75
Finally, we divide both sides of the equation by 0.25 to isolate x:
x = 8.75 / 0.25
Solving this:
x = 35
Therefore, the call lasted for 35 additional minutes, in addition to the first minute.
To find the total number of minutes, we need to add the first minute to the additional minutes:
Total minutes = 1 + 35 = 36
So, the call lasted for 36 minutes.