a is half good a work man as b and together they finish a job in 14 days . in how many days working alone b finish the job ?
"c 21 wc = 1 : 2 2 x + x = 1 / 14 = > x = 1 / 42 2 x = 1 / 21 = > 21 days"
multiply(14, divide(const_3, const_2))