In a game Alis and Daniel shoot arrows on a circular target with a radius of R.

Alis throws arrows such that their distance from the center have Continuous uniform distribution (0,R) - o,R are the parameters for uniform distribution.

While Daniel throws arrows such that their distance from the center have random Continuous uniform distribution (From the target)

I was asked to calculate the expected value for the distance of the arrows for both participant.

For Alis it's R/2 but what about Daniel? I didn't understand what's given about him, what are the parameters for him...

I claimed: "For Alis it's R/2" Proof:

The expected value for random variable with uniform distribution (a,b) (with parameters a and b) is (a+b)/2