15% of 3000 cars is (15/100)*3000 = <<(15/100)*3000=450>>450 cars
40% of 3000 cars is (40/100)*3000 = <<(40/100)*3000=1200>>1200 cars
450+1200 = <<450+1200=1650>>1650 cars which cost either less than $15000 or more than $20000
Out of 3000 cars, there will then be 3000-1650 = <<3000-1650=1350>>1350 cars left which cost between $15000 and $20000
#### 1350