What's the largest 5-digit number that is a multiple of both 4 and 9?

Question

Please answer quickly

Answer 1

The largest 5-digit number is 99972. This is the largest divisible by 36, the product of 4 and 9 and was obtained by dividing 99999 (the largest 5-digit number) by 36 (or dividing 11111 by 4), taking the integer part of the quotient and then multiplying this integer by 36. 11111/4=2777+3/4. Integer part is 2777, multiplied by 36=99972.

Answer 2

4=2*2
9=3*3

So the least common multiple of all these numbers is :
36
100000/36=2777.77
36*2777=99972
36*2787=100008

Hence 99972 is largest 5-digit number that is a multiple of both 4 and 9

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