Use a coordinate system: Let the direction of the current be the positive x-axis, then the direction in which the fish is swimming forms the positive y-axis:
.... and ....
Then the resulting velocity is
Calculate the length of the vector. If then ....I've got
to #b): This question has to be done in exactly the same way.
Do you mean W55°N or do you mean N55°W? I'll take the first version. If this is wrong then you know at least how to do the problem.
Use a coordinate system according the geographical directions. The positive x-axis is pointing East, the positive y-axis is pointing North.
Then the first part of the way of the fox is:
........... and the second part is:
The displacement is ..........I've got