Answer:
Tauren has 78 keychains
James has 34 keychains
Marcus has 68 keychains
Yahya has 74 keychains
Explanation:
I got this answer by doing this:
If Tauren has 78 keychains then its gonna be left like that.
If everybody else has an average of 68 keychains then divide 68 by 2 to get half of what marcus has which equals 34.
Then add the amount of James and marcus keychains which is 68 plus 34 which equals 102, the subtract the 28 because it says Yayha has 28 fewer keychains and that equals 74.