Cards in a pack are black or red in the ratio black : red=2 : 5

What fraction of the cards are red?

5/7

Step-by-step explanation:

There are 5 red cards and 7 cards in total. Add the number of black card, 2, to the number of red cards, 5, to get the total number of cards. Then, put the number of red cards as the numerator an the total number of cards as the denominator.

Feel free to correct me if I'm wrong