Problem: if two integers x , y ( x > y ) are selected from - 10 to 1 ( inclusive ) , how many possible cases are there ?
Rationale: "if two integers x , y ( x > y ) are selected from - 10 to 9 ( inclusive ) , how many possible cases are there ? a . 150 b . 180 c . 190 d . 210 e . 240 - - > 12 c 2 = 12 * 11 / 2 = 66 . therefore , the answer is b ."
annotated_formula: add(add(add(add(add(add(add(1, 10), add(1, const_2)), add(1, const_1)), 1), 10), const_2), const_1)