Answer: 3,000 years
The professor mentions near the beginning of the episode that the Mummy of Anchor is over 3,000 years old.
From Quiz: Scooby Doo: Where Are You?
Answer: Red Beard
Someone was stealing all of one company's freighters by using a mysterious ghost ship. It turns out that it was the "Ghost of Redbeard" who was stealing all of the ships. Red Beard's ghost actually turned out to be the freighter company's owner C.L. Magnus who was trying to get more money by "stealing" the freighter and selling its cargo for more money.
From Quiz: "Scooby Doo" Trivia
Answer: Don Messick
Don Messick provided the voice of Scooby Doo until suffering a stroke in 1996, at a cartoon recording studio, and officially retiring a week later.
From Quiz: Scooby Doo: Where Are You?
Answer: Fred
When Mystery Inc. sees that all the lights in Funland turn on even though it's months before it is supposed to open, they go to investigate and see all the booths are up and running. Fred goes over to the milk bottle booth and tries to knock them all down. Afterwards, he gets a prize, and when they turn back around the milk bottles are up again.
From Quiz: "Scooby Doo" Trivia
Answer: Casey Kasem
Casey Kasem was the original 'American Top 40' countdown host and creator as well as the voice of Norville 'Shaggy' Rogers.
From Quiz: Scooby Doo: Where Are You?
Answer: Scooby Snacks
Shaggy and Scooby are always the ones who get scared, but they're also the fastest, so the other members of the gang have to find something that will get them to go be bait for the monster/ghost/zombie, whatever it is. Scooby Snacks are the only thing that can get them to go.
From Quiz: "Scooby Doo" Trivia
Answer: 'no deposit, no return'
Velma follows this by saying "Big Help!" with an extremely sarcastic tone.
From Quiz: Scooby Doo: Where Are You?
Answer: suction cups
He finds suction cups, which turn out to be a vital clue in the case. At first, they think that the culprit is Helga the housemaid, but when they find the suction cups, they know that it's not her, because she used to perform in the circus and wouldn't need suction cups to climb a building.
From Quiz: "Scooby Doo" Trivia
Answer: Franken Castle
The gang visits Franken Castle. Weatherby estate was introduced in the episode "What the Hex Going On?". Haunted Isle was from the episode "Hassle in the Castle". Gold City was the setting for the episode "Mine Your Own Business".
From Quiz: Scooby Doo: Where Are You?
Answer: Green Ghosts
Scooby has to spend the night at a haunted mansion if he wants to get some money that was left in a will for him. There are people who are trying to scare him off, and they dress up as Phantom Shadows or Green Ghosts.
From Quiz: "Scooby Doo" Trivia
