a is half good a work man as b and together they finish a job in 10 days . in how many days working alone b finish the job ?
"c 15 wc = 1 : 2 2 x + x = 1 / 10 = > x = 1 / 30 2 x = 1 / 15 = > 15 days"
multiply(10, divide(const_3, const_2))