Here, the first number is 11, which divided by 4 leave remainder 3 between 10 and 300.
And the next number is 15 and the next is 19
Last term before 300 is 299, which divided by 4 leave remainder 3.
So, the list is
11, 15, 19, …, 299
Clearly, This is an AP
With first term, a = 11
Common difference, d = 15 - 11 = 4
Last term, an = 299
Using the nth term formula
an = a + (n - 1)d
299 = 11 + (n - 1) (- 4)
299 - 11 = (n - 1) (- 4)
288 = (n - 1) (- 4)
n - 1 = 72
n = 73
So there are 73 numbers between 10 and 300 which leaves 3 as remainder when divided by 4.
