Problem: the sum of all the integers k such that – 21 < k < 24 is
Rationale: "- 20 - - - - - - - - - - - - - - - - - - 0 - - - - - - - - - - - - - - - - - 23 values upto + 23 cancels outwe are left with only - 20 - 19 sum of which is - 39 . hence option d . d"
annotated_formula: add(add(negate(21), const_1), add(add(negate(21), const_1), const_1))