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Assume it takes n years:
In the case of having it repaired, in n years, the total cost would be: 300 + 75n dollars
In the case of buying a new one, in n years, the total cost would be: 500 + 75(1-60%)n dollars
300 + 75n = 500 + 75(1-60%)n
n = 40/9
If you have to use an integer for n, n would be 5 (the smallest integer greater than 40/9)
1年前
5