Problem 38 Answer
Draw a 6 by 6 square. Plot the arrival time of one person vertically. Plot
the arrival time of the other person horizontally. The times they arrive
within 10 minutes of each other can be represented by a diagonal stripe
across the square. The area of the entire square is 36. The area of the portions
outside the stripe is 25. Thus the area of the stripe is 11. Considering the
uniformity of the arrival times the probability of arriving within ten
minutes is the area of the stripe divided by the area of the square = 11/36.
Michael Shackleford, A.S.A.