Mark has 60% 12 sided dice, so 60/100 * 10 dice in his bag = <<60/100*10=6>>6 12 sided dice.
James has 75% 12 sided dice, so 75/100 * 8 dice in his bag = <<75/100*8=6>>6 12 sided dice.
They will need to purchase 14 dice - 6 dice - 6 dice = <<14-6-6=2>>2 dice.
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