The Main Challenge
Following on from DAY 240, here’s another one of the unique Keith Number challenges made famous by Mike Keith and similar to the Fibonacci sequence. If you like playing around with numbers, you’ll love having a go at this fun concept.
The 1st 2-digit Keith Number, 14, is worked out by following a pattern:
- 1 4 5 9 14
1+4=5; 4+5=9; 5+9=14 (the total arrives back to the original number).
The 2nd 2-digit Keith Number, 19, is worked out in a similar way:
- 1 9 10 19
1+9=10; 9+10=19 (the total again arrives back to the original number).
By following this pattern, the 3rd and 4th 2-digit Keith Numbers are 28 and 47:
- 2 8 10 18 28
- 4 7 11 18 29 47
Can you continue this process and locate the only other two Keith Numbers below 100?
The 7puzzle Challenge
The playing board of the 7puzzle game is a 7-by-7 grid of 49 different numbers, ranging from 2 up to 84.
The 2nd & 3rd rows contain the following fourteen numbers:
8 13 17 25 28 36 42 45 48 55 63 64 66 80
What is the sum of the square numbers?
The Factors Challenge
Which of the following numbers are factors of 292?
6 8 10 12 14 16 18 None of them
The Mathematically Possible Challenge
Using 8, 10 and 12 once each, with + – × ÷ available, which are the only TWO numbers it is possible to make from the list below?
1 4 9 16 25 36 49 64 81 100
#SquareNumbers
The Target Challenge
Can you arrive at 292 by inserting 2, 3, 4, 5 and 6 into the gaps below?
- ◯×(◯³×◯²+(◯–◯)²) = 292
Answers can be found here.
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