Manhattan Prep
Phone plan A charges $1.25 for the first minute and $0.15 for every minute thereafter. Phone plan B charges a $0.90 connection fee and $0.20 per minute. Which of the following equations could be used to find the length, in minutes, of a phone call that costs the same under either plan?
A. 1.25 + 0.15x = 0.90x + 0.20
B. 1.25 + 0.15x = 0.90 + 0.20x
C. 1.25 + 0.15(x - 1) = 0.90 + 0.20x
D. 1.25 + 0.15(x - 1) = 0.90 + 0.20(x - 1)
E. 1.25 + 0.15x + 0.90x + 0.20 = x
OA C
Phone plan A charges $1.25 for the first minute and $0.15
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Phone plan A charges $1.25 for the first minute and $0.15 for every minute thereafter.AAPL wrote:Manhattan Prep
Phone plan A charges $1.25 for the first minute and $0.15 for every minute thereafter. Phone plan B charges a $0.90 connection fee and $0.20 per minute. Which of the following equations could be used to find the length, in minutes, of a phone call that costs the same under either plan?
A. 1.25 + 0.15x = 0.90x + 0.20
B. 1.25 + 0.15x = 0.90 + 0.20x
C. 1.25 + 0.15(x - 1) = 0.90 + 0.20x
D. 1.25 + 0.15(x - 1) = 0.90 + 0.20(x - 1)
E. 1.25 + 0.15x + 0.90x + 0.20 = x
OA C
Let x = total duration of phone call (in minutes)
So, the cost of an x-minute call = $1.25 + ($0.15)(x - 1)
ASIDE: I created the expression ($0.15)(x - 1) because we pay $1.25 for the FIRST minute. So, if x = the TOTAL call time, then x-1 = the time spent AFTER the first minute)
Phone plan B charges a $0.90 connection fee and $0.20 per minute.
Let x = total duration of phone call (in minutes)
So, the cost of an x-minute call = $0.90 + ($0.20)(x)
Which of the following equations could be used to find the length, in minutes, of a phone call that costs the same under either plan?
We need: $1.25 + ($0.15)(x - 1) = $0.90 + ($0.20)(x)
Answer: C
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Brent
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AAPL wrote:Manhattan Prep
Phone plan A charges $1.25 for the first minute and $0.15 for every minute thereafter. Phone plan B charges a $0.90 connection fee and $0.20 per minute. Which of the following equations could be used to find the length, in minutes, of a phone call that costs the same under either plan?
A. 1.25 + 0.15x = 0.90x + 0.20
B. 1.25 + 0.15x = 0.90 + 0.20x
C. 1.25 + 0.15(x - 1) = 0.90 + 0.20x
D. 1.25 + 0.15(x - 1) = 0.90 + 0.20(x - 1)
E. 1.25 + 0.15x + 0.90x + 0.20 = x
OA C
We can create the equation in which x = the number of minutes that equates the charges of the two plans. Plan A charges $1.25 for the first minute and $0.15 for the remaining (x - 1) minutes. Plan B charges a $0.90 fee and $0.20 for all x minutes of the call. Thus, the equation that equates the charges for the two plans is:
1.25 + 0.15(x - 1) = 0.9 + 0.2x
Answer: C
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