Mathematics for IGCSE & O level - Probability (Section 3 - No. 39)
A bag contains 7 white balls, 3 black balls. What's the probability of picking a black ball?
3/10
7/10
3/7
7/3
Giải thích
There are 3 black balls out of a total of 10 balls. Thus, the probability of picking a black ball is 3/10.