Medium is
a. the materials used by an artist.
b. the aesthetic balance an artist achieves in his/her work of art.
c. the relation of one part to another, or of parts to the whole.
d. a reproduction of people, places, or things.

Medium is the material used by an artist.

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min

+15-35=-20

going in opposite directions