Express 31 by 4 successive digits, using no more than 4 out of 5 basic operations (i.e. + - / * and exponentation), nothing else allowed.
The order of the digits must be an arithmetic progression like 8*7-6-5 or 3+4*5+6, examples fitting the specifications but not the result.
a. Straightforward answers:
4^3/2-1 ....might be others
b. Including concatenation (not precluded by the text!):
2+34-5 .....might be others
c, Extra challenge: Disregard the order, as long as you use
only digits a, a+1, a+2, a+3:
54-23 ....plenty of others
The challenge is to expand lists a. b. and c. without introducing new operators - still no brackets.
Will publish the comprehensive expanded solution.
Edited on August 14, 2018, 3:49 am