How to use Shard Key to get Target Query

Ops and Admin Sharding
1

I have collection with this shard key.

{ first: 1, second: 1 }

Can anyone ensure me which queries of these will get Target Query ?

db.Collection.find( { first: 10, second: { $lte: 'string' } } ) // Only This One I think
db.Collection.find( { second: { $gte: 20 } } )
db.Collection.find( { first: { $gt: 10 } } )

I believe only the first query will work as Target Query, as it uses two shard key with two filters.

You may let me clarify me if I am wrong about it.