the sum of the non - prime numbers between 20 and 30 , non - inclusive , is
"sum of consecutive integers from 21 to 29 , inclusive = = = = > ( a 1 + an ) / 2 * # of terms = ( 21 + 29 ) / 2 * 9 = 25 * 9 = 225 sum of non - prime numbers b / w 20 and 30 , non inclusive = = = > 225 - 52 ( i . e . , 23 + 29 , being the prime # s in the range ) = 173 answer : a"
add(add(add(add(add(add(add(20, const_1), add(add(20, const_1), const_1)), add(add(add(20, const_1), const_1), const_2)), add(add(add(add(20, const_1), const_1), const_2), const_1)), add(add(add(add(add(20, const_1), const_1), const_2), const_1), const_1)), add(add(add(add(add(add(20, const_1), const_1), const_2), const_1), const_1), const_1)), add(add(add(add(add(add(add(20, const_1), const_1), const_2), const_1), const_1), const_1), const_1))