The 1 in 60 would be good for an estimate, and in your first question there are a few bits missing surely. Are you assuming that when each of the two bearings are taken that you are the same distance from the NDB? Also do you not need the GS as opposed to the TAS since the TAS will not give you a distance to work the equation (unless nil wind and ISA sea level conditions)
If so then take half the distance covered (x) and half the angular diference (y). You should then be able to work out the range using x/Sin y=Distance from NDB
This is assuming the above points...
Second problem is very similar your distance is X the angluar difference is Y and the distance between the points is Z, use X=2(Sin(Y/2) x Z)
Its all the Tan Cos Sin rules realy plus some lateral thinking..
good luck I passed so anyone can!!