If i won 2 blue cards for every 3 grey cards i lost, and i won 8 blue cards altogether, what else is true? a. i lost 12 grey cards. b. i won 10 blue cards c. i won 12 cards. d. i lost 24 grey cards.

If you won 2 blue cards, then you lose 3 grey cards
If you won 4 blue cards, then you lost 6 grey cards (multiply by 2)
If you won 6 blue cards, then you lost 9 grey cards (multiply by 3)
If you won 8 blue cards, then you lost 12 grey cards (multiply by 4)

A) you lost 12 grey cards

Another way to see this answer is to solve the proportion below
2/3 = 8/x
2*x = 8*3
2x = 24
x = 24/2
x = 12