Puzzle 205
What number comes next in this sequence:
7 · 8 · 5 · 5 · 3 · 4 · 4 · ?
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Answer
6: the numbers denote the number of letters each month has starting with January, therefore August has 6 letters.
Puzzle 206
Here we have a rectangular room, measuring 30 feet by 12 feet, and 12 feet high.
There is a spider in the middle of one of the end walls, 1 foot from the ceiling (A).
There is a fly in the middle of the opposite wall, 1 foot from the floor (B).
What is the shortest distance that the spider must crawl in order to reach the fly?
The Spider and the Fly, The Canterbury Puzzles, Henry Ernest Dudeney.
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Hint
Going down and across the floor isn't the only route.
Answer
40 feet.
Explanation Diagram
If you imagine the room to be a cardboard box, you can 'unfold' the room in various ways, and each route gives a different answer.
We can use Pythagoras' theorem (a2 + b2 = c2) to calculate the distances:
distance2 = horizontal2 + vertical2
distance = √(horizontal2 + vertical2)
Route #1
distance = 1 + 30 + 11 = 42 feet.
Route #2
horizontal = 6 + 30 + 6 = 42 feet.
vertical = 10 feet.
distance = √(422 + 102) ≈ 43.174 feet.
Route #3
horizontal = 1 + 30 + 6 = 37 feet.
vertical = 6 + 11 = 17 feet.
distance = √(372 + 172) ≈ 43.178 feet.
Route #4
horizontal = 1 + 30 + 1 = 32 feet.
vertical = 6 + 12 + 6 = 24 feet.
distance = √(322 + 242) = 40 feet.
Puzzle 207
Three builders are laying a brick wall.
Freddie can lay 1,000 bricks in three hours, Jimmy can lay 1,000 bricks in two hours and Kevin can lay 1,000 bricks in six hours.
How long will it take Freddie, Jimmy, and Kevin to lay 1,000 bricks if they all work together?
Puzzle Copyright © Kevin Stone
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Hint
How many bricks are laid in six hours?
Answer
1 hour.
Reasoning
How many bricks are laid in six hours?
In six hours, Kevin lays 1000 bricks, Freddie lays 2000 bricks, and Jimmy lays 3000 bricks.
So, in six hours, we have a total of 6000 bricks laid.
Which means that it will take one hour to lay 1000 bricks.
Puzzle 208
Can you find every occurrence of the word MARCH that appears in this grid (horizontally, vertically, or diagonally)?
The hint will reveal the number of times it occurs, but where are they?
Note: this puzzle is not interactive, and the letters cannot be selected.
Puzzle Copyright © Kevin Stone
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Hint
The word MARCH appears 46 times.
Answer
The word MARCH appears 46 times.
