Mathematics for IGCSE & O level - Probability (Section 4 - No. 11)
In a bag with 6 red balls and 4 black balls. What is the probability of selecting one of each color, if the ball is not replaced?
2/15
8/45
12/20
1/2
Vysvětlení
P(red then black) + P(black then red) = (6/10*4/9) + (4/10*6/9) = 24/90 + 24/90 = 48/90 = 8/15.