Updated at 8 p.m. June 27: Our contest is now closed, and no more guesses will be posted. Thanks to everyone who took a shot at answering!

The correct answer: According to ENERGY STAR, about 60 percent of U.S. light sockets still hold an inefficient bulb.

We’ll pick randomly from among the 20 people who guessed the correct answer. If you’re chosen as the winner, we’ll directly contact you using the email address you gave us when you posted your answer.

Thanks for playing, and watch around this time next month for our next energy efficiency trivia question!

Ready to take your shot at winning a $50 Amazon gift card? You’ll have a chance if you correctly answer today’s energy efficiency trivia question. It’s the first in a series of questions we plan to post this summer and fall.

The full official rules are here, but here’s the short version:

  • Each question will be posted here on our Stories blog at 8 a.m. on contest day. (We’ll promote them on social media beforehand — particularly on Twitter and Facebook — so be sure you’re following us.)
  •  You’ll have until 8 p.m. that same day to post your answer in the Comments section of the blog post. Answers posted on any other social media platform, or posted after 8 p.m. on contest day, will not be eligible to win. Be aware that it may take a few minutes for your comment to show up on the blog — no need to enter it multiple times.
  • One correct response will be chosen at random, and the winner will receive a $50 Amazon gift card. Make sure to leave a valid email address as part of your comment, so we can reach you if you win — if we can’t reach you, we’ll have to choose another winner.

Also, we reserve the right to hide or delete comments not related to the contest. If you need help with a customer service issue, the best way to handle it is to call us at 1-800-DIAL-PPL (that’s 800-342-5775.)

Now that that’s out of the way, here’s this month’s energy efficiency trivia question. Remember, answers go in the comments:

According to ENERGY STAR, what percentage of U.S. light sockets still hold an inefficient bulb?