This is another number formation question. You must use each of 2, 1 and 8 exactly twice to make the number 2018. The rules are
- Allowed symbols: +, −, ×, ÷, (, ), √, !. Arbitrary functions (such as the logarithm) are not allowed.
- The ordering of the numbers are not important.
- It is OK to use numbers as superscript (exponent or the power for the radical symbol).
- Concatenation is allowed although using (2+1)1 to construct 31 is not allowed.
- Ceiling or flooring is not allowed. 211÷2=105.5, not 105 or 106.
The use of decimal point or scientific notation is not allowed.
For example, (2+8)×(2+1)!×√1+8=180
is a valid construction, although this is not a solution because it does not equal 2018.
Edit (after slvrbld posted his answer): Try to make 2108 and 8102 as well if you can.
(And of course, the more ways the better).
Second Edit I am thinking whether I can make all 4-digit numbers composed of 2, 0, 1 and 8 (numbers beginning with 0 do not count). I have solutions for some but not all of them. Once I find solution for all of them or find a well defined subset for which I have solutions, I will update it and make it a formal challenge here.
Answer
A possible solution:
1×2+8!/(12+8)
Edit: more obscure approach:
(8×81×1×2)+2=(642)+2=2018
No comments:
Post a Comment