Hint
One possible answer begins with the letter A.
Answer
ark: bark, dark, market, parking, shark.
or:
ill: bill, dill, millet, pilling, shill.
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Puzzle 130
If I was in Florida and dropped a heavy ball into a bucket of water which was at a temperature of 45 °F and dropped another identical ball into an identical bucket of water at a temperature of 25 °F …
… which ball would hit the bottom of the bucket first?
Hint
There are two different methods, one involves a cube root, and the other doesn't require a calculator.
Answer
9 x 11 x 13.
Reasoning #1
We're after three numbers that multiply together, so a good place to start is the cube root of 1,287, which is roughly 10.88.
Let's try dividing by the closest odd number to 10.88:
1287 ÷ 11 = 117
We're now after whole divisors of 117. Trying the odd numbers either side of 11 might work.
Trying either 9 or 13 gives the answer:
9 x 11 x 13 = 1,287
Trying the closest odd number to the cube root always works, and the other two numbers are the odd numbers either side.
Reasoning #2
We after three numbers that multiply together, but none of these can end in 5 (otherwise our answer would end in 0 or 5).
So, they can only end in 7, 9, 1 (e.g. 87, 89, 91), or 9, 1, 3 (e.g. 89, 91, 93).
However, if they ended in 7, 9, 1, the answer would end in 3 (because 7 x 9 x 1 = 63).
Therefore, they end in 9, 1, and 3 (because 9 x 1 x 3 = 27).
The first numbers we can try are 9, 11, 13:
= 9 x 11 x 13
= 99 x 13
= 100 x 13 - 13
= 1300 - 13
= 1,287
A calculator is not required!
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Puzzle 132
My BrainBashers electronic world atlas has developed another fault, I did a listing of miles from England to particular countries and here is the result:
Chile 800 miles
Wales 4,200 miles
France 1,100 miles
Italy 3,400 miles