How many numbers lie between the largest three-digit number and the largest four-digit number which are divisible by 5?

Correct option is C

​Given:

Largest 3-digit number = 999.

Largest 4-digit number = 9999.

Solution:
First number divisible by 5: 1000.
Last number divisible by 5: 9995.

Total numbers:

​$$\frac{9995 - 1000}{5} + 1 = 1800$$​​