A group of boys has an average weight of 36 kg. One boy weighing 42 kg leaves the group and another boy weighing 30 kg joins the group. If the average now becomes 35.7 kg, then how many boys are there in the group?
A and B together can complete a work in 24 days. B alone does 1/3rd part ofthis work in 12 days. How many days will A alone take to complete the remaining work?