At a Tech Pvt Ltd. there are some engineering students employed as trainee engineers, belong to two eminent institutions of India. One group belongs to IIT and another to NIT. Each student of IIT works for 10 hours a day till 60 days and each student of NIT works for 8 hours a day till 80 days on the two same project. The ratio of students of IIT and that of NIT is 4:5 respectively. Students of which institution is slower in work and by how much?