At a certain gas station, 40% of the customers use regular unleaded gas (A₁), 35% use extra unleaded gas (A₂), and 25% use premium unleaded gas (A3). Of those using regular gas, only 30% fill their tanks (event B). Of those customers using extra gas, 60% fill their tanks, whereas of those using premium, 50% fill their tanks.

a. What are the simple events in this scenario?
b. What is the relationship between the simple events? Explain.
c. Draw a diagram that illustrates the relationship. Label the probabilities and events.