Five ten-sided rolls in strictly increasing order

A fair die with faces $1$ to $10$ is rolled five times. The probability that each roll is strictly larger than the one before is $\dfrac{x}{10^5}$. Find $x$.

$252$. A strictly increasing sequence is the same as a choice of 5 distinct values, since each such set can be listed increasingly in exactly one way. So there are $\binom{10}{5}=252$ favourable sequences out of $10^5$.