a and b together can complete a piece of work in 4 days . if a alone can complete the same work in 12 days , in how many days can b alone complete that work ?
"a and b ' s one day work = 1 / 4 a ' s 1 day ' s work = 1 / 12 b ' s 1 day ' s work = ( 1 / 4 ) - ( 1 / 12 ) = 2 / 12 = 1 / 6 hence b alone can complete the work in 6 days . answer is option c"
divide(const_1, subtract(divide(const_1, 4), divide(const_1, 12)))