a gambler has won 40 % of his 20 poker games for the week so far . if , all of a sudden , his luck changes and he begins winning 80 % of the time , how many more games must he play to end up winning 60 % of all his games for the week ?
"let x be the number of additional games the gambler needs to play . 0.4 ( 20 ) + 0.8 x = 0.6 ( x + 20 ) 0.2 x = 4 x = 20 the answer is a ."
divide(subtract(multiply(20, divide(60, const_100)), multiply(20, divide(40, const_100))), subtract(divide(80, const_100), divide(60, const_100)))