This is sometimes confusing........many people think that the answer - at first blush - should be "22"...however.........n mod m refers to the difference beween "n" and the greatest multiple of "m" that is less than or equal to "n" ......if "n" is multiple of "m"....then..... n mod m = 0
The greatest multiple of 116 that is less than or equal to -138 is - 232....and the difference beween -232 and - 138 is 94....so -138 mod 116 = 94