Mathematics for IGCSE & O level - Probability (Section 8 - No. 23)
A bag contains only red and white marbles. If the probability of drawing a red marble is 0.4, what is the probability of drawing a white marble?
0.4
0.5
0.6
1.0
Explication
The probabilities of all possible outcomes must sum to 1. So, 1 - 0.4 = 0.6.