Mathematics for IGCSE & O level - Probability (Section 1 - No. 47)
A box contains 3 red balls, 4 green balls, and 5 blue balls. What is the probability of picking a green or red ball?
1/4
1/2
7/12
5/12
解释
There are 3+4=7 favorable outcomes (red or green) out of 12 total outcomes. Probability= 7/12