An electrical company decides to replace the lightbulbs in all of the non working street lights on two specific streets. The company learns that 2/3 of the lights do not work on the first street and 1/6 of the lights do not work on the second street. What is the total fractional portion of the non working lights on these two streets?
The first street has 2/3 of its lights broken, which means that it has 2/3 * 1 = <<2/3*1=2/3>>2/3 of its lights broken.
The second street has 1/6 of its lights broken, which means that it has 1/6 * 1 = <<1/6*1=1/6>>1/6 of its lights broken.
So the total fractional portion of non working lights on these two streets is 2/3 + 1/6 = <<2/3+1/6=2/3+1/6=5/6>>5/6. Answer: \boxed{\frac{5}{6}}.