Mathematics for IGCSE & O level - Probability (Section 3 - No. 33)
A box contains 20 marbles: 8 are red, 7 are blue, and 5 are green. What is the probability of selecting a red marble?
2/5
7/20
1/4
4/5
설명
There are 8 red marbles out of 20 total. 8/20 simplifies to 2/5, also written as 40%