Create 10 mathematical expressions equal to 100. Each should use as few instances as possible of a single digit (0 through 9.)
You may use any common operation (+, -, *, /, ^, √, !, [], parentheses, concatenation.)
First let me write down two generic solutions, applicable to any digit in the range 2 to 9:
a. 100=(kkk-kk)/k (kkk means concatenation of 3 k's) - so we can express 100 by 6 identical digits (5 digits in the case of k=1, since the division by 1 is unneeded.
Only operations listed in the puzzle are used.
Later I will publish specific solutions for each digit, onlyfor cases where 100 is achieved in less than 6 uses of said digit.
b. If the word base were allowed to appear in the solution then in the range 2 to 9:
k*k=100(base k); using 3 k's only.
Just now I do not remember alI my expressions, so I will mention only: 111-11;- 33*3+3/3;- 4!*4+4;- (5+5)*(5+5); 99+9/9…and promise to return later with the missing solutions ....
(out of time now!).
Edited on May 17, 2014, 1:28 pm