Problem: if the mean of numbers 28 , x , 42 , 78 , 82 and 104 is 62 , then what is the mean of 128 , 255 , 511 , 1023 and x ?
Rationale: "the mean of numbers 28 , x , 42 , 78 and 104 is 62 : 28 + x + 42 + 78 + 82 + 104 = 62 * 6 - - > x = 38 ; so , the mean of 128 , 255 , 511 , 1023 and x is ( 128 + 255 + 511 + 1023 + 38 ) / 5 = 391 . answer : c ."
annotated_formula: divide(add(add(add(add(subtract(multiply(104, add(const_4, const_1)), add(add(add(28, 42), 78), 82)), 62), 128), 255), 511), add(const_4, const_1))