If one third (1/3) of his picks are blue, then 3 times the total number of blue picks equals his total pick count, or 3*12=36 picks
If half of the picks are red, then he has 36/2=<<36/2=18>>18 red picks
If the rest of the picks are yellow, then he has 36-18-12=<<36-18-12=6>>6 yellow picks
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