It’s the Friday Puzzle!

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Solution on Monday.

Imagine a test with 26 questions.  When you get a question wrong you are deducted 5 points.  When you get a question right you are given 8 points.  If you answered all of the questions, and had a final score of 0 points, how many questions did you answer correctly?

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

Answer to the Friday Puzzle….

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First, if you are around Edinburgh, I am giving a talk tonight at the International Magic Festival on the psychology of magic and illusion.  Details here.

Second, on Friday I set this puzzle…

A long playing record has a 12 inch diameter.  The unused bit in the middle is about 4 inches in diameter, and there is a smooth outer edge one inch wide around the recording.  If there are 91 grooves to the inch, roughly how far does the needle move during the recording?

If you have not tried to solve it, have a go now.  For everyone else the answer is after the break.

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It’s the Friday Puzzle….

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Solution on Monday.

A long playing record has a 12 inch diameter.  The unused bit in the middle is about 4 inches in diameter, and there is a smooth outer edge one inch wide around the recording.  If there are 91 grooves to the inch, roughly how far does the needle move during the recording?

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

It’s the Friday Puzzle!

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Solution on Monday.

A shop sells chocolates for £1 each, and you can exchange 3 wrappers for 1 chocolate. If you start off with £15, how many chocolates can you buy?

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

Answer to the Friday Puzzle….

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coverOn Friday I posted these puzzles.  If you have not tried to solve them, have a go now.  For everyone else, the answer if after the break…

1) How many times can you subtract the number two from the number fifty?

2) You drive a bus from London to Edinburgh. At the first bus stop, 43 people get in. At the second stop, 9 more people get in. At the third stop, 45 passengers step off and 12 people get in. After nine hours, the bus arrives in Edinburgh.  What is the name of the driver?

Continue reading

It’s the Friday Puzzle!

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Two puzzles this week!  Solutions on Monday.

1) How many times can you subtract the number two from the number fifty?

2) You drive a bus from London to Edinburgh. At the first bus stop, 43 people get in. At the second stop, 9 more people get in. At the third stop, 45 passengers step off and 12 people get in. After nine hours, the bus arrives in Edinburgh.  What is the name of the driver?

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

It’s the Friday Puzzle!

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Two puzzles this week!  Solutions on Monday.

1) What 5-letter word actually becomes shorter when you add two letters to it?

2) Find a number less than 100 that is increased by one-fifth of its value when its digits are reversed.

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.