In a video game, Gate 3 is open 40% of the time and Gate 4 is open 20% of the time. The chance of both gates being open at the same time is 15%. Draw a tree and Venn diagram (with probabilities labeled) to model the scenario. What is the P(Gate 3 and Gate 4 are both open)?
A.60%
B.15%
C.100%
D.0%