Hi there!
To find your answer, you'll need to use the cross product method :
3 minutes = 54 baskets
1 minute = X baskets
(54 × 1) ÷ 3 = X baskets
54 ÷ 3 = X baskets
18 = X
So your answer is: he shots 18 baskets per minute.
There you go! I really hope this helped, if there's anything just let me know! :)