There are 4 slots in the row.  He can choose two of them for his IMO medals in $\binom{4}{2} = \boxed{6}$ ways.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
A mathematical prodigy wishes to put 2 of his indistinguishable IMO gold medals and 2 of his indistinguishable IPhO gold medals in one row. How many distinct arrangements are possible?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
6
A mathematical prodigy wishes to put 2 of his indistinguishable IMO gold medals and 2 of his indistinguishable IPhO gold medals in one row. How many distinct arrangements are possible?
test