119
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114
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112
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109
votes
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93
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78
votes
Accepted
77
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76
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74
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71
votes
3:3! It's a football score!
Since the puzzle oddly and specifically mentions the symbol for the square root, I used this:
but rotated and reflected it giving:
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67
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64
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63
votes
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62
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60
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58
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56
votes
Accepted
Create all numbers from 0-100 only using all of 1,2,3,4 and 5
Also, you can use any operation.
Ok then.
$\begin{array}{c|c}
0 & \log_{\frac1 2} \left( \log_{4!!-3} 5 \right) \\
1 & \log_{\frac1 2} \left( \log_{4!!-3} \sqrt 5 \right) \\
2 & \log_{\...
- 753
54
votes
Accepted
Making 103 from 4 zeroes
As
rand al’thor points out
in the solution built upon here,
there must be a way to formulate a
$\small 3$ with only
two $\small 0 \kern1mu$s.
How promising that...
&...
- 21.8k
53
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52
votes
Accepted
A clock for 2017
With the digits in order:
$$
\begin{align}
1 &= 2 + 0 - 1 ^ 7 \\
2 &= 2 + 0 \times 1 \times 7 \\
3 &= 2 + 0 + 1 ^ 7 \\
4 &= -2 - 0 - 1 + 7 \\
5 &= 2 \times (0 - 1) + 7 \\
6 &= ...
- 18.6k
52
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52
votes
Accepted
Make 5 5 5 5 = 19
Here's one way I found:
Or, using just the characters explicitly allowed in the question:
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49
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48
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A clock for 2017
I tried to make a digital clock.
$0 = (7 + 1 + 2) \times 0$
$1 = (2 + 7 + 1) ^ 0$
$2 = (7 + 1) \times 0 + 2$
$3 = 7 \times 0 + 2 + 1$
$4 = 2 \times 7 - 10$
$5 = 7 - 2 + 1 \times 0$
$6 = 7 - 1 + 2 \...
- 17.9k
48
votes
Accepted
Doubling/tripling puzzle: make 1 from 1536 in as few steps as possible
As Jo has already shown, this can be accomplished in
To help visualize this problem, we can imagine:
Proving minimality:
- 7,119
47
votes
Accepted
46
votes
Combine 1,3,3,7 to get 10
As quite standard in this kind of hard number puzzle, we can:
Another example of this form being the only solution is:
Use 1, 2, 3, 8 to make 28
with the unique (up to commutation) solution being:
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43
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How to get 5 from 0,0,0 and 1?
First off, latest edit - just for fun, how to get 5 from just 0 and 1:
Before rule change posted:
With the changed rules:
And while we're at it, here's $0$ to $28$:
And here's how to get 5 from ...
- 9,411
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votes
Only top scored, non community-wiki answers of a minimum length are eligible