Find the odds against choosing a red marble

Question

You can randomly choose a marble from a bag. There are 10 black marbles, 8 red marbles, 4 white marbles, and 6 blue marbles in your “bag of marbles.” Find the odds against choosing a red marble 

1. 8:22= 2:11
2. 20:8 = 5: 2
3. 8/28= 2/7
4. 28/8 = 7/2

Answer 1

THere not red is 20 and red is, so odds against redis 20/8 = 5/2