a is twice as good a workman as b and together they finish a piece of work in 18 days . in how many days will a alone finish the work ?
"if a takes x days to do a work then b takes 2 x days to do the same work . - - > 1 / x + 1 / 2 x = 1 / 18 - - > 3 / 2 x = 1 / 18 - - > x = 27 days . hence , a alone can finish the work in 27 days . answer : c ."
multiply(add(const_1, const_2), 18)