Question

Two traffic lights operate independently. Your probability of being stopped at the first one is 0.4 and your probability of being stopped at the second one is 0.7. The probability at being stopped at the first light and second light is 0.3. What is your probability of being stopped at the first light or second light?Make sure to show your work. NEED HELP ASAP. The correct answer was .8 I just don't know how. Thank you.

Answer 1

0.54 or 54%

Explanation:

P( 1st but not second) = P(1st) - P(1st and Second) = 0.4 - 0.28 = 0.12 = 12%

P( 2nd but not first) = P(2nd) - P(1st and Second) = 0.7 - 0.28 = 0.42 = 42%

Probability of 1 of them (exactly one) = P( 1st but not second) + P( 2nd but not first) = 0.12 (12%) + 0.42 (42%) = 0.54 or also 54%.

Hope this helps!