The answer to your question is 7.375
The radius is half the diameter of the circle. If the radius gets larger then the whole circle grows. When the circle gets larger, the area gets larger too.
Submarine: -730
Airplane: 9,144
|-730-9,144|=|-9,874|=9,874
|d|: absolute value
The vertical distance between the submarine and airplane is 9,874 meters.
the last two ones be the same, the outcomes would be TTT,HTT,THH,HHH
so the probability is 4/8 = 1/2.
