Answer:
37.5 or about 38 water bottles
Explanation:
$1.50 x 50 (license plate holders sold times price per)
$75
$150 - $75 (Total price minus amount from license plate holders)
$75
$75 / $2.00 (Remainder divided by the amount of each water bottle)
gets you 37.5 or about 38 water bottles to sell
Let me know if this helps/is correct :)