Using the numbers 1, 3, 4 and 6, and the operations +, -, x, and / can you come up with the numbers from 1 to 20? You must use the numbers 1, 3, 4 and 6 exactly once in each calculation. You may use brackets as part of your work. For example:
1 = 4 x 1+ 3 - 6
2 = 4 + 3 - 6 + 1
3 = (6 + 3) / (4 - 1)
Solution:
1 = 4 x 1+ 3 - 6
2 = 4 + 3 - 6 + 1
3 = (6 + 3) / (4 - 1)
4 = (6 - 4) x (3 - 1)
5 = 4 x 3 - 6 - 1
6 = 6 - 4 +3 + 1
7 = 4 x 3 - 6 +1
8 = 6 + 4 - 3 +1
9 = (6 - 3) x (4-1)
10 = (4 + 1) x 6 / 3
11 = (6 - 3) x 4 - 1
12 = 6 + 4 + 3 - 1
13 = 6 x 3 - 4 - 1
14 = 1 + 3 + 4 + 6
15 = 6 x 3 - 4 +1
16 = 4 x (6 - 3 + 1)
17 = 4 x 3 +6 -1
18 = 4 x 3 + 6 x 1
19 = 4 x 3 + 6 +1
20 = 6 x 4 - 3 - 1
Using 1, 3, 4, and 6 can you come up with 21, 22 and 23? How about 24?
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