i cant put in a full explanation for some reason so the answer is 108.
Since AP is a chord of both circles,
the base is 24 and by Pythagorean theorem, the other leg is 7. (7*24)/2 = 84. 84 is the answer.
8 hours is equal to 480 minutes. So 480/2 = 240. Multiplying 15 by 240 gives 3600 tin cans.
there are 8*10^6 = 8,000,000 total phone numbers
