Amulet it says "you throw onto", in other words, that even "your" darts landed on the globe.
The probability of where the first dart doesn't matter.
There are 2 lots of hemispheres the dart can land onto... N- E-W.
The second dart has to hit same or adjacent quadrant. So (1/4 + 1/2) = 3/4
The third dart, given the 1/3 chance the second dart hits the correct quadrant, has a (1/4 + 1/2) = 3/4 chance. If the 2/3 chance eventuates and the second dart hits an adjacent quadrant, then the third dart has a 1/2 chance of hitting the correct hemisphere.
