Answer
I asked for 7 feet, 4 inches and Alex brought me 4 feet, 7 inches.
Reasoning
If we label what I asked for as A feet and B inches, which is (12 x A + B) inches, then I actually received B feet and A inches, which is (12 x B + A) inches. Which means that:
5/8 x (12 x A + B) = (12 x B + A)
Simplifying gives:
A = 91/52 x B
As B is the number of inches, it can only be between 1 and 12 and must give A as a whole number of feet.
B = 4 is the only possible value, which means that A = 7.
So I originally asked for 7 feet, 4 inches.
Double-Checking
I received 4 feet, 7 inches = 55 inches.
I asked for 7 feet, 4 inches = 88 inches, and 88 x 5/8 = 55.
??
Puzzle 159
Our local scrap merchant had to travel to the county recycling plant, 60 miles away.
On the way there, the wagon was fully laden, so could only manage a steady 12mph.
On the way back, the wagon was much lighter and could manage a steady 16mph.
The wagon started with 24 gallons of fuel in the tank ready for the round trip, which was easily enough fuel as the wagon managed to travel 8 miles for each gallon.
Unfortunately, a piece of metal had pierced the fuel pipe at the very start of the trip, and the wagon began to lose 1 gallon of fuel every hour.
Luckily, it only lost fuel when moving and lost no fuel while unloading the scrap metal.
Were the 24 gallons enough for the entire round trip?