$(100-2\times46)\div(3-2)=8$ 
A total of $$46$$ bicycles and tricycles are in the garage. If there are $$100$$ wheels in total, there should be~\uline{~~~~~~~~~~}~tricycles in the garage. 
[1] $$8$$ 
[2] $$12$$ 
[3] $$24$$ 
[4] $$38$$ 
[5] $$6$$ 