Answer:
8 positive integers.
Explanation:
One value of n would be 15 because 225 = 15^2.
Other values are 225 * n where 15n <= 1000 and n is a perfect square.
So n = 4 gives us 225* 4 = 900 which is a perfect square and 15*4 = 60.
n = 9 gives us 225 * 9 which is a perfect square and 15*9 = 135.
n = 16 gives us 225*16 and 15*16 = 240 , so OK.
n = 25 gives a perfect square and and 15*25 = 375 - so OK.
n = 36 gives a perfect square and 15*36 = 540 - so OK.
n = 49 gives a perfect square and 15*49 = 735 - so OK.
n = 64 gives a perfect square and 15*64 = 960 - so ok.
n = 81 gives a perfect square and 15 * 81 = 1215 so NOT ok.