Friday Puzzler 2 -- a+b-c=d
Alex Y
In case that other one is too easy, try this.
a+b-c=d
You need to find the values for a, b, c, and d so that the equation above is true in four different senses:
1) Taken as the normal arithmetical sense, e.g. 45+15-5=55
2) Taken as operating on the sets of digits in each number. e.g., 45+15-5 = 154, because {4,5} U {1,5) = {4,5,5,1}; take away {5}, and d can be any number made up of [all] the digits in {1,4,5}
3) Taken as operating in the same way on the sets of Roman Numerals in that representation of the equation,
4) Taken as operating on the sets of letters in the equation with each of a,b,c,and d spelled out in the English words for the numbers. E.g., forty-five + fifteen - five = whatever number you can spell using [all] the letters {e,e,f,f,f,i,n,o,r,t,t,y} (I'm pretty sure there is not one)
