You own a weird calculator with only 4 buttons, which perform the following 4 operations: ×3 +7 -11 ÷2.
Your challenge is increment the numbers below by pushing only a certain number of buttons on the calculator. For example, 1 → 2 with 3 buttons has solution: +7 ÷2 ÷2.
Each puzzle below has a unique solution.
1. 5 → 6 with 2 buttons
2. 6 → 7 with 2 buttons
3. 12 → 13 with 2 buttons
4. 13 → 14 with 3 buttons
5. 19 → 20 with 3 buttons
6. 26 → 27 with 3 buttons
7. 4 → 5 with 4 buttons
8. 30 → 31 with 4 buttons
9. 47 → 48 with 4 buttons
10. 61 → 62 with 5 buttons
11. 69 → 70 with 5 buttons
12. 87 → 88 with 5 buttons
13. 42 → 43 with 6 buttons
14. 60 → 61 with 6 buttons
15. 75 → 76 with 6 buttons
16. 117 → 118 with 7 buttons
17. 127 → 128 with 7 buttons
18. 139 → 140 with 7 buttons
The answers are here.