Hint
It doesn't matter what the distance is, so try a random distance.
Answer
This cannot be done.
It does not matter how far the trip is, let's assume that it is random distance, say 60 miles, and remembering that Time = Distance ÷ Speed.
The morning trip took 60 miles ÷ 30 mph = 2 hours.
To average the required 60 mph, we would have to travel the total distance (of 120 miles) in 2 hours. However, we've already used all of the two hours for the morning trip!
Choosing any random distance would also show that it can't be done.
During a recent police investigation, Chief Inspector Stone was interviewing five local villains to try to identify who stole the prize cake from the mid-summers fayre. Below is a summary of their statements:
Alex: it wasn't Emery
it was Billie
Billie: it wasn't Charlie
it wasn't Emery
Charlie: it was Emery
it wasn't Alex
Dale: it was Charlie
it was Billie
Emery: it was Dale
it wasn't Alex
It was well known that each suspect told exactly one lie. Can you determine who stole the cake?
Reasoning
Looking at Billie's statements, one of the statements was a lie and the other was the truth. Therefore, it must have been either Charlie or Emery.
Looking at Dale's statements, for the same reason, it was either Charlie or Billie.
Therefore, it must have been Charlie who committed the crime.
Double-checking this against the other statements confirms this.
?
Puzzle 8
I was travelling from Chesterton to Newcastle recently when I came across a sign which had fallen off its post at the crossroads.
It was marked to Newcastle, Chesterton, Knutton and Silverdale.
Unfortunately I didn't know which road to take to Newcastle and had hoped the sign would help.
Luckily I had a brainwave which helped me put the sign back pointing correctly to Newcastle.
