How many numbers lie between 10 and 300, which divided by 4 leave a remainder 3?


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.


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