Ram and Shyam can complete a task in \(6{ 2\over 3}\)days and 15 days, respectively. They work together for 4 days, and then Ram leaves. In how many days after Ram leaves, will Shyam complete the remaining task alone?
A, B and C can complete a certain work in 30 days. B and C together can complete the same work in 45 days. If B is 20% more efficient than A, then B alone can complete one-third of the same work in: