Explanation:

Total numbers = (800 - 200) + 1 = 601
Number of terms which divide by 5
l = 800
a = 200
Common difference(d) = 5
l = a + (n-1)d
800 = 200 + (n - 1)5
n-1 = 120
n = 121
Number of terms which divide by 7
l = 798
a = 203
Common difference(d) = 7
l = a + (n-1)d
798 = 203 + (n - 1)7
n-1 = 85
n = 86
Number of terms which divide by 5 and 7
l = 770
a = 210
Common difference(d) = 35
l = a + (n-1)d
770 = 210 + (n - 1)35
n-1 = 16
n = 17
Number of terms which divide by either 5 or 7 = 121 + 86 - 17 = 190
Number of terms which divide by neither 5 nor 7 = 601 - 190 = 411