How many three digit natural number are divisible by 4?

The least 3 digit natural number divisible by 4 is 100 and the largest 3 digit natural number divisible by 4 is 996.

Here , a = 100, d = 4 and tn = 996

We know that,

tn  = a + (n – 1 ) d

∴ 996 = 100 + (n – 1 )4

∴ 996 – 100 = 4 (n – 1)

∴ 896/4 = n – 1

∴ 224 = n – 1

∴ 224  + 1 = n

∴ n = 225