the sum of all the integers k such that – 20 < k < 24 is
"- 19 - - - - - - - - - - - - - - - - - - 0 - - - - - - - - - - - - - - - - - 23 values upto + 23 cancels outwe are left with only - 19 - 18 sum of which is - 37 . hence option d . e"
add(add(negate(20), const_1), add(add(negate(20), const_1), const_1))