a , band c can do a piece of work in 11 days , 45 days and 55 days respectively , working alone . how soon can the work be done if a is assisted by band c on alternate days ?
"( a + b ) ' s 1 day ' s work = 1 / 11 + 1 / 45 = 56 / 495 ( a + c ) ' s 1 day ' s work = 1 / 11 + 1 / 55 = 6 / 55 work done in 2 day ' s = 56 / 495 + 6 / 55 = 2 / 9 2 / 9 th work done in 2 days work done = 9 / 2 * 2 = 9 days answer : c"
divide(55, divide(add(add(divide(55, 11), divide(55, 45)), add(divide(55, 11), divide(55, 55))), const_2))