David M. answered 12/09/18
Dave "The Math Whiz"
The previous tutor is correct that it has to be an even number for it to be divisible by 4 and Y has to be 0 for it to be divisible by 5. So we know that Y is 0. For the number to be divisible by 9 the sum of all the digits must add up to a number that is also divisible by 9. So far we have 24X80 which adds up to 2+4+X+8+0=14+X. Seeing as X can only be a single number from 0 to 9 the only number that can be added to 14 that the total sum will equal to a number that can be divisible by 9 is 4: 2+4+4+8+0=18 which is divisible by 9. Therefore, X=4 and Y=0. You can check this by dividing the number, 24480, by 4, 5 and 9 and you will see that this is correct.