1,234
The least three-digit number that is divisible by both 5 and 9 is 135.
99,600 is the largest 5-digit number that meets both requirements.
How about: 108
99999
54.
27000
2400
54
Any number whose last digit is 0 would be divisible by both these numbers. 1000, 1010, 1020...
9990 is one such number.
9000 is one such number.
A 4-digit number divisible by both 5 and 9 must be divisible by their least common multiple, which is 45. To find a 4-digit number divisible by 45, we need to find a number that ends in 0 and is divisible by 45. The smallest 4-digit number that fits these criteria is 1005 (45 x 22 = 990, and adding 15 gives us 1005).