How to convert the probability P/Q to P⋅Q−1 where Q is co-prime with mod I was dealing with probability in programming but i was stuck on the final answer part.

Below is statement in which format i have to give the answer

Can you find the probabilities It can be proved that for each of these values, the probability can be expressed as a fraction PQ, where P and Q are integers (P≥0, Q>0) and Q is co-prime with 998,244,353. You should compute P⋅Q−1 modulo 998,244,353 for each of these values. 

Below is probability that can be calculated on paper and 2nd line is for what i have to print can any1 explain how should calculate P.Q-1.

For 1st Input
Calculated Probability = 1/4 
Answer : 748683265
For 2nd Input
Calculated Probability was = 1/16 , 3/16 , 3/16 , 9/16
Answer that was given = 436731905 935854081 811073537 811073537


If anything is unclear then pls comment as iam new to community I am not very good at asking questions.
Thank you for your reply in advance.
$$\frac{p}{q} \equiv p \cdot q^{-1} \mod 998244353$$

Since $q$ is coprime with $998244353$, $q^{-1}$ always exist. It can be found using extended euclidean algorithm, shown here.

For example, $\frac{1}{4} \equiv 4^{-1} \mod 998244353$.

You can check that $4 \cdot 748683265 = 2994733060 \equiv 1 \mod 998244353$,

so $4^{-1} \equiv 748683265 \mod 998244353$.
This can be solved using Extended Euclidean Algorithm. You can visit the following link for further info and code solutions:

https://www.geeksforgeeks.org/multiplicative-inverse-under-modulo-m/

Also there is a same question on overflow for this.