Question 444908
Let C1 = the cost of plan 1
Let C2 = the cost of plan 2
Let x = the number of minutes used
For the costs of the two plans we can write:
C1 = 50 + 0.35(x - 500) [x >= 500]
C2 = 75 + 0.45(x - 1000) [x >= 1000]
Set C1 = C2, since the costs are equal:
50 + 0.35(x - 500) = 75 + 0.45(x - 1000)
Solve for x:
50 + 0.35x - 175 = 75 + 0.45x - 450
0.1x = 250
x = 2500
Ans: 2500 minutes
Check:
C1 = 50 + 0.35(2500-500) = 50 + 700 = 750
C2 = 75 + 0.45(2500-1000) = 75 + 675 = 750