Directions: Create a three digit number using the whole numbers 0-9 no more than one time each. Try to create the number divisible by the greatest (or fewest) number of the following factors: 2, 3, 4, 5, 6, 8, 9 or 10.
What should the three digits add up to so that it is divisible by 3 and 9?
What should the middle digit be so that it is divisible by 4?
Fewest number of factors: any three digit prime with unique digits would have none of the given numbers as factors. There are more than 20 such numbers (e.g. 103, 347, 521, 849).
Source: Kelly Zinck