Hello,
numbers: 1000,1005,1010,1015,1020,....,9995
-1000=.....0,......5,......,10,..,15,.......20,....,8995
:5=...........0.......1..........2.......3.........4......1799
+1=..........1.......2..........3.......4.........5......1800
Answer : 1800 multiples.
