ENTRY LINK
Say Yes to the Dress in Las Vegas Sweeps: Games & More: TLC
NO PENALTY IF YOU GET THE QUESTION WRONG

Grand Prize: a trip for the winner and one guest to Las Vegas. The Grand Prize also includes two tickets to Beatles Love, and 2 nights at The Mirage Resort and Casino and round trip coach air travel for two people to Las Vegas, NV from a major commercial airport near winner's residence (as determined by Sponsor), double-occupancy hotel accommodations for 2 nights Winner must take trip with in one year, or prize will be forfeited in its entirety. Total approximate retail value ("ARV") of Grand Prize is $3,500

And the rules link:
Say Yes to the Dress In Las Vegas Sweeps Official Rules: Games & More: TLC