a can do a piece of work in 6 days . b can do it in 5 days . with the assistance of c they completed the work in 2 days . find in how many days can c alone do it ?
"c = 1 / 2 - 1 / 6 - 1 / 5 = 2 / 15 = > 7.5 days answer : d"
divide(multiply(6, 5), divide(subtract(multiply(6, 5), multiply(add(divide(multiply(6, 5), 6), divide(multiply(6, 5), 5)), 2)), 2))