A positive integer n is called strictly ascending its digits are in the increasing order e-g- 2368 and 147 are strictly ascending but 43679 is not- The number of strictly ascending numbers - 10-9- is2-9- - 12-9-2-9- - 19-

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Toppr Admin · Accepted Answer

A positive integer n is called strictly ascending if its digits are in the increasing order e.g. 2368 and 147 are strictly ascending but 43679 is not. The number of strictly ascending numbers <109 is29−12929+19!

A positive integer $n$ is called strictly ascending if its digits are in the increasing order e.g. $2368$ and $147$ are strictly ascending but $43679$ is not. The number of strictly ascending numbers $< 10^{9}$ is
$2^{9} - 1$
$2^{9}$
$2^{9} + 1$
$9!$