I noticed that some problems allow multiple solutions ie. http://www.4clojure.com/problem/14 allows at least 5 lines, each being a solution (as long as they all eval to "8")
But some ie. http://www.4clojure.com/problem/15 only allows one solution (can't use more than 1 line)
EDIT: Since I'm new at clojure, thanks to @amalloy , I was made aware of why the above happens.