hav 450$ tu spend on 18$ tires & 15$ kits
simpel wae start with 1kit, 450-15$=435$...435/18=24 tires
2...2 kits=450-30$=420$ 420/18=23 tires
3...10 kits=150$, 450-150=300$, 300/18=16 tires
4...15 kits=225$, 450-225=225, 225/18=12 tires
5...1 tire=18$, 450-18=432$, 432/15=28 kits
take yer pik