
First, you must figure out which letter to keep in each of the four letter strings.
does not count – keep the letter that is not a roman numeral
impose order – keep the letter that when removed makes the remaining three stand in alphabetical order
forex – keep the letter that when removed makes the remaining letters spell out the acronym for a common currency
was it a bat i saw – this is a palindrome; keep the letter that is symmetrical around its vertical center axis.
odd one out – keep the letter that has an odd index in the alphabet, A = 1 as usual
no note – keep the letter that is not a musical note
not in line – keep the letter that is not in the word “line”
without letting go – keep the letter that does not require lifting the pen from the paper when drawing it (I’m a bit unsure of the explanation to this one, this was the most reasonable one I could come up with)
no pressure – bar is a unit of pressure, remove the o
melt – keep the letter that remains when frozen water melts 😉
Now comes the second part. Click the image to see a set of mathematical expressions.

Convert the letter you kept in the first row to a number (A=1 as usual). Here the expression is only a ?, so just assign that number to the bat variable.
Next, convert the letter you found in the second row to a number and substitute ? for it, then substitute the bat with what you found from the first row. Calculate the resulting expression and take what you get modulo 26. Assign the result to the chain variable.
I suggest using the searchbox on Google for the calculations, it can handle very large numbers. Type in e.g. (23 + 12^2 + 18^4 )^3 % 26 and you will see what I mean.
Next, convert the letter you kept in the third row to a number and substitute the ? in the third expression for it, substituting the chain and the bat from what you previously obtained. Evaluate the expression %26 and assign the result to the grim reaper variable.
Keep doing this until you know the value of all symbols. Convert those values to letters (A=1 etc) and the right column will spell out your answer from bottom to top.
Since the answer is not anagrammed, and since not all expressions contain all previous symbols, it is possible to solve this riddle without getting all the letters in the initial step right.













