for the past n days , the average ( arithmetic mean ) daily production at a company was 50 units . if today ' s production of 60 units raises the average to 55 units per day , what is the value of n ?
"( average production for n days ) * n = ( total production for n days ) - - > 50 n = ( total production for n days ) ; ( total production for n days ) + 60 = ( average production for n + 1 days ) * ( n + 1 ) - - > 50 n + 60 = 55 * ( n + 1 ) - - > n = 1 . answer : e ."
subtract(divide(subtract(60, 50), subtract(55, 50)), const_1)