Here are the steps:
- Find the total number of marbles. This is equal to 5+8+4+3=20 marbles in all.
- Probability of getting blue=number of blue marbles/total number of marbles=5/20=1/4
- Following same formula as on top, Red=8/20=2/5
- Probability of getting a marble NOT white. Add all marbles except white/total number of marbles=16 marbles/20 marbles=4/5