We have to find the numbers between 101 and 999 which are divisible by both 2 and 5.
That means the numbers divisible by 10 between 101 and 999.
Let, the required divisible numbers be,
110, 120, 130, …, 990
a = 110, d = 10, last term, l = 990
Number of terms,
= 89
Hence, the number of natural numbers between 101 and 999 which are divisible by both 2 and 5 are 89.