⟩ A car has run 10000 miles using 5 treys interchangeably, To have a equal worn out by all treys how many miles each Tyre should have run?
each tire with 8000 miles
2 2
2 2 reserve tire=0miles now change the tire,
after 2000miles
2 4
4 4 reserve tire=2000miles
after 2000miles
4 4
6 6 reserve tire=4000miles now change the tire,
after 2000miles
6 6
8 6 reserve tire=6000
after 2000miles
8 8
8 8 reserve tire=8000
so ans is 8000.