5 skilled workers can do work 20 days So, 1 worker can do 100 day Similarly 8 semi skilled can do in 25 day 1 semi skilled do in 200 day 10 unskilled do in 30 day 1 unskilled do in 300 day So, number of days for 2 skilled, 6 semi-skilled and, 5 unskilled workers are given by