The total number of blue cards in the game = 48
Explanation:
Total number of blue and yellow cards = 84
let the blue card denote B and yellow card as Y
B = 4
Y = 3
Total number of cards in one round = 7
number of rounds possible = total number of cards / number of cards in one round
= 84/7
= 12
number of blue cards = 12 x 4
= 48
The total number of blue cards in the game = 48