On your daily commute, you never know what type of driving conditions you will face. Either an accident or road construction on your commute will cause traffic and make you late for work. There is a 30% chance of an accident, a 10% chance of construction, and a 60% chance of no traffic.
What is the probability that you will run into traffic? Type your answer as a decimal between 0 and 1 (e.g., 10% = 0.1).
P(traffic) = 1 − P(no traffic) = 1 − 0.6 = 0.4. You could also add P(accident) + P(construction) = 0.3 + 0.1 — the complement rule just gets you there faster, especially when an event has many pieces.
0.6 is the probability of no traffic — the question asks for its complement. P(traffic) = 1 − P(no traffic). Try again.
0.3 is just the chance of an accident — but construction also causes traffic. Add both causes, or use the complement: 1 − P(no traffic). Try again.
0.1 is just the chance of construction — accidents also cause traffic. Add both causes, or use the complement: 1 − P(no traffic). Try again.
It looks like you entered a percent — please answer as a decimal between 0 and 1 (e.g., 40% = 0.4).
Traffic happens when there is an accident (30%) or construction (10%). Or take the shortcut: P(traffic) = 1 − P(no traffic) = 1 − 0.6. Try again.