Question

1. In 1963, how many percent of the skaters finished the race?

2. In 1963, how many percents of the skaters finished the race?

3. In 1963, how much percent of the skaters finished the race?

4. Only one percent of the skaters finished the race.(answer)
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Which questions are correct from 1 to 3? Do you have other suitable questions?

Answer 1

None of the first three questions is correct. Here's how to re-phrase:

In 1963, what percent of the skaters finished the race?