The question is asking you to calculate the frequency of C# based on an equal-tempered scale and a frequency for A of 429.3Hz.
The portion of the homework assignment that you deleted between the first and second versions of your questions gives an example of a similar calculation, using a different value for the frequency of A and seeking to calculate the frequency of a different note.
So you should, as the problem suggests, calculate the pitch of B when A is 440 Hz to confirm that you arrive at the correct answer. Then you should be fairly confident that you can calculate B when A is 429.3 Hz.
But the problem, of course, is to calculate C#, not B. So you also need to figure out what is different about that calculation. The difference lies here:
the pitch of B4 can be found by multiplying 440 by the square of the twelfth root of two, since B is two semitones above A and each semitone raises the pitch by the 12th root of 2.
C# is not two semitones above A, so the frequency of C# is not to be found by multiplying by the square of the 12th root of 2. Part of your task is to find the actual factor you need to use instead.