instruction:
In this task, you're given a context, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both context and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the context or linked information.
question:
Context: Built by Polish engineer Thaddeus Kosciuszko under the command of George Washington, Fort Mercer was built in 1777 Link Information: Andrzej Tadeusz Bonawentura Kościuszko (; 4 or 12 February 1746  Answer: 31
answer:
How old was the engineer who built Fort Mercer when it was built?


question:
Context: In 1978, he moved to the Fort Lauderdale Strikers of the North American Soccer League. Link Information: none Answer: none
answer:
Was Marine Cano the starter for the Fort Lauderdale Strikers in 1978?


question:
Context: His best-known work was a live radio broadcast on WTOP, a CBS Radio affiliate, covering the state funeral of President John F. Kennedy. Link Information: About 1,200 invited guests attended the funeral Mass in the cathedral. Answer: 1,200
answer:

How many people attended the event that Raiford covered on a live radio broadcast and is considered his best known work?