Six men, whose names are Fred Alberts, Larry Smith, Brian Martin, Marty Jones, Bill Edison, and John Fox were in an elevator together.
Suddenly, the lights went out. When the lights came back on, Fred Alberts' wallet was missing.
Detectives have investigated. They have questioned the suspects, the witnesses, and people who know the suspects. They have collected physical evidence (hair samples, fibre samples, etc.) from the crime scene. They have collected 14 clues, but have not been able to solve the crime.
Therefore, they have called in the world's greatest detective, YOU. You must now examine the clues and solve the crime.
No two suspects have the same weight, colour shoes, colour umbrella, colour car, or hair colour.
The suspect who owns a purple car was wearing tan shoes.
The suspect who weighs 180 pounds owns a green car.
Brian Martin owns a green car.
The suspect who owns a black car was wearing blue shoes.
The suspect who weighs 150 pounds was wearing tan shoes.
Marty Jones was carrying a purple umbrella.
John Fox has red hair.
Larry Smith weighs 210 pounds.
The suspect who weighs 190 pounds was wearing blue shoes.
The suspect who was carrying a red umbrella is not the one who was wearing black shoes.
The thief owns a black car.
The suspect who owns a white car is not the one who weighs 170 pounds.
Bill Edison was wearing brown shoes.
The suspect who weighs 190 pounds is not the one who has red hair.
Hint: You can either fix the distance rowed and see what numbers work, or you can fix the number of hours.
Answer: 12 miles.
In the morning, rowing at 2 miles per hour, they rowed for 6 hours. In the afternoon, rowing at 4 miles per hour, they rowed for 3 hours.
There are a number of ways of working this out, and here are two of them:
If we assume the distance the rowed upstream to be D miles, we know the morning took (D ÷ 2) hours, and the afternoon took (D ÷ 4) hours, with a difference of 3 hours. So:
D D 3
- - - =
Multiplying throughout by 2, and then 4, gives:
4D - 2D = 24
2D = 24
D = 12 miles.
They rowed 12 miles upstream.
If we assume they rowed for H hours upstream, we know they travelled H x 2 miles in the morning. In the afternoon they rowed for (H - 3) hours, and travelled (H - 3) x 4 miles. We know these distances are the same, so:
2H = (H - 3) x 4
2H = 4H - 12
12 = 2H
H = 6 hours.
They rowed for 6 hours upstream at 2 miles per hour, which is a total of 12 miles.
Starting in the bottom left corner and moving either up or right, adding up the numbers along the way, what is the largest sum which can be made?