a is twice as good a workman as b and they took 8 days together to do the work b alone can do it in ?
"wc = 2 : 1 2 x + x = 1 / 8 x = 1 / 24 = > 24 days answer : e"
multiply(divide(multiply(8, add(const_2, const_1)), const_2), const_2)