That's very like the old tongue twister about Peter Piper, busby.
"Peter Piper picked a peck of pickled pepper. IF Peter Piper picked a peck of pickled pepper, where's the peck of pickled pepper, Peter Piper picked?"
If 3 can pick 4 in 2 mins,
then 1 can pick 4/3 in 2 mins ie 4/6 in 1 min
so 1 can pick 4/6 x 60 in 60 mins ie 1 can pick 40 in 60 mins
therefore 5 can pick 200 in 60 mins