The ratio of Doug's sports cards to Philip's sports cards was 7:5. When Doug gave 3 sports cards to Philip, they each had the same amount. How many sports cards did they have altogether?

Answer 1

Ratio of Doug’s sports cards to Philip’s sports cards: 7 + 5 = 12
Doug gives Philip 3 sports cards: 12 * 3 = 36
They have 36 sports cards altogether

Answer 2

7 * 3 = 21
5 * 3 = 15
21 + 15 = 36
36 sports cards

Answer 3

algebraic solution:

Doug had 7x and Phil had 5x
after the gifting:
Doug had 7x-3 , Phil had 5x+3
now they have the same, so
7x - 3 = 6x + 3
x = 6

total is 7x+5x = 12x = 12(6) = 36