# what is the probability that you get a prime number when you pick two random numbers between 0 and 1 ,a and b, and divide b by a and round up?

what is the probability that you get a prime number when you pick two random numbers between 0 and 1, a and b, and divide b by a and round up?

let's say your random numbers where 0.09121=a, and 0.6163=b, b/a=6.8665 and rounding up you get 7

It will be $$\sum\limits_{p\text{ prime}} \dfrac1{2p(p-1)} \approx 0.3866$$