What is the smallest number after 8000 that is divisible by 4 and 9?

Answer 1

By 'after 8000' it looks like 'greater than 8000' is what you want.

So to get multiple of 4, last 2 digits must be a multiple of 4. {This is because 100 and every multiple of 100 are multiples of 4, so you only have to look at the last two digits}.

For multiple of 9, digits must sum up to 9 (or multiple of 9). So 8001 sums up to 9, but it's not multiple of 4. 8010 doesn't work either. So let's look at digits sum to 18. We already have 8, so the last 2 digits sum to 10 would work, and the last 2 digits multiple of 4:

• 19 : 1+9 = 10, but not multiple of 4.
• 28 : 2+8 = 10, and yes it's a multiple of 4.

8028 is the answer.