Question

How many odd 4-digit numbers divisible by 5 are there less than 5000?

Answer 1

So, we only consider 4-digit numbers of the form _ _ _ 5. 
The first blank can only be 1,2,3,4, while the other two can be any digit 0 to 9. 

So, there are 4 * 10^2 = 400 such numbers. 

I hope this helps!