Here $$1712040, 1704382$$ and $$1702497$$ are all $$7-$$digits numbers in which the same numbers 1 and 7 are placed at ten lakhs and lakhs places respectively whereas the digits in ten thousands place are $$1, 0$$ and $$0$$
Hence $$1712040$$ is the largest number and the digits in the remaining two numbers at thousands place are $$4$$ and $$2$$
Since $$4 > 2$$
Therefore $$1704382 > 1702497$$
$$201200, 200175$$ and $$199988$$ are $$6-$$digits numbers in which $$2$$ and $$1$$ are at lakhs place respectively
Since $$2$$ is greater than $$1$$
Therefore $$201200 > 200175$$
Thus $$199988$$ is the smallest number
The given numbers in the descending order are:
$$1712040 > 1704382 > 1702497 > 201200 > 200175 >199988$$