3. Round the difference between the largest and smallest five-digit numbers with distinct digits that are divisible by 15 to the nearest ten.
3. It holds that $15=3 \cdot 5$.

From divisibility by 5, it follows that the units digits of the desired five-digit numbers are 0 or 5, and from divisibility by 3 that the sum of their digits is divisible by 3.

2 POINTS

The smallest such number is 10245, and the largest is 98760.

2 POINTS

Their difference is 88515,

1 POINT

and the rounded value is 88520.

1 POINT

TOTAL 6 POINTS

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