How many perfect squares less than 1000 are divisible by 8.
1 4 9 16 25 36 49 64 81 100 121 144 169 196 225 256 289 324 361 400 441 484 529 576 625
676 729 784 841 900 961 every 4th one..... count 'em
$8 = 2^3$
$2^4, 2^6, 2^8$
$2^4 \cdot {3^2, 5^2, 7^2}$
$2^6 \cdot {3^2}$
$3+3+1=\boxed{7}$
+36915 
+874 
