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Christmas card 2022
2022-12-04
In November, I spent some time (with help from TD) designing this year's Chalkdust puzzle Christmas card.
The card looks boring at first glance, but contains 11 puzzles. By colouring in the answers to the puzzles on the front of the card in black (each answer appears twice), then colouring remaining squares
containing 0s red, and regions containing a star brown,
you will reveal a Christmas themed picture.
If you want to try the card yourself, you can download this printable A4 pdf. Alternatively, you can find the puzzles below and type the answers in the boxes. The answers will automatically be found and coloured in black, and appropriate squares and regions will be coloured red and brown...
The puzzles | ||
1. | What is the only prime number that is both two more than a prime number and two less than a prime number? | Answer |
2. | Holly adds up the first 7 odd numbers. What total does she get? | Answer |
3. | Holly next adds up the first \(n\) odd numbers to get a total of 1089. What is \(n\)? | Answer |
4. | Ivy starts with 0 then adds or subtracts some multiples of 4 or 7. What is the smallest positive integer that she could have ended with? | Answer |
5. | Ivy again starts with 0, but this time she adds or subtracts some multiples of 240 or 400. What is the smallest positive integer that she could have ended with? | Answer |
6. | How many 4-digit integers are there whose digits are all non-zero and whose digits add up to 7? | Answer |
7. | How many positive integers are there whose digits are all non-zero and whose digits add up to 7? | Answer |
8. | Eve wrote down a four-digit number. Eve then removed one of the digits of her number to make a three-digit number. The sum of her two numbers is 3119. What was her four-digit number? | Answer |
9. | Eve wrote down a five-digit number. Eve then removed one of the digits of her number to make a four-digit number. The sum of her two numbers is 96158. What is the largest number that her five-digit number could have been? | Answer |
10. | Noel drew 12 points on the circumference of a circle, then drew a straight line connecting every pair of points. How many lines did he draw? | Answer |
11. | Noel drew some points on the circumference of a circle, then drew a straight line connecting every pair of points. He drew 2926 lines. How many points did he draw? | Answer |
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Comments
Comments in green were written by me. Comments in blue were not written by me.
2022-12-20
@Nicki: If you're correct the picture should look suitably ChristmassyMatthew
×1
Great fun thanks. At first they seem impossible but then a way through appears! How do I get the answers / check if I’m right?
Graeme Johnston
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