Question 672094: An overseas call is charged at one rate(a fixed amount) for the first minute and at a different rate for each additional minute. if a 7 minute call costs $10, and a 4 minute call costs $6.40, find the rate.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! An overseas call is charged at one rate(a fixed amount) for the first minute and at a different rate for each additional minute. if a 7 minute call costs $10, and a 4 minute call costs $6.40, find the rate.
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Let fixed amount be "x" and additional rate be "y":
Equation:
x + 6y = 1000 cents
x + 3y = 640 cents
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Subtract and solve for "y":
3y = 360
y = $1.20 (added minutes rate)
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solve for "x":
x + 3*120 = 640
x + 360 = 640
x = $2.80 (1st minute rate)
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Cheers,
Stan H.
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