PROBLEM 1. Find the correct average speed for this 10 mile round trip.

Your second problem is a train problem, and to further the summer theme it is a re-run of a problem that I used in the Echoes 10 years ago. Previous solvers will receive full credit if they can reconstruct their solutions.

PROBLEM 2. Find a way to switch the positions of the freight cars C1 and C2. The locomotive E starts on the main line PQ. It can push or pull one or both freight cars from its front or back . The switch at S can be thrown either direction, but there is only room for one freight car along track SR and the locomotive is too long for track SR.

You offered a great variety of correct solutions for the time between eclipses with an accurate watch. The ‘winners’ noted that there are 11 eclipses in 12 hours and thus time between = 12/11 hours.

The correct answer to the second watch problem was 121 hours. Many of you found the answer to be 120 hours. I have given full credit to the engineering graduates for this incorrect answer since the error was less than 1%. "That’s close enough for government work."

Alumni solvers of the fall problems are: Dick Mott (1943), Jim Hurt (1948), Al Schairbaum (1949), Paul Gottfried (1949), Jack Marshall (1950), Charles Hirschfield (1954), Art Sutton (1956), Charles E. Cooper (1956), Harold Brown (1957), Jim Edds (1958), Cecil Ambuehl (1958), David Bailey (1959), John Tindall (1961), Fred Terry (1962), Mike Gilpatrick (1962), Joe Born (1970), Allan K. Mahler (1971), David Jordan (1971), Randy Collins (1973), Al Rhone (1974), Paul Chilson (1974), Terry Chapman (1975), Donald Zona (1977), Jerry Matthews (1977), Scott Warner (1978), Jay Slupesky (1979), Rich Priem (1979), Jeff Koechling (1980), Scott Bagwell (1980), Bill Flight (1984), Loren Cook (1985), Bob Wright (1986), Brian Seidl (1987), Steve Moore (M.S. 1988), Chris Abdnour (1989), Albert Rhone (1990), Ben Steele (1990), Bob Burger (1991), Todd Anderson (1992), Ernie Snider (1996), Mike Pilcher (1996), Jason M. Bumgardner (1997), Tyson Patterson (1997), Beau D’Arcy (2003), Bret Olson (2003), Brian Miller (2003), Gordon Thompson (2003), Jennifer Klingenberg (2003), Jesse McQuiston (2003), Jim Ginther (2003), John Mastin (2003), Joseph Wyman (2003), Kahle Bopp (2003), Kert Gelipse (2003), Thomas Markle (2003), Tim Kibbey (2003), and Joseph Hickman (2003). Friends solving the problem are: Kevin Duffy, Neil Flatter, Dick Goldstein,and Paul E. Stallman.