Sports competition is organized in a college every year. 50% of total students participated in 1^st year, out of which 40 students participated in 1^st year only. 64% of students participated in 2^nd year, out of which 50 students participated in 2^nd year only. 74% of students participated in 3^rd year, out of which 70 students participated in 3^rd year only. How many students participated in both 2^nd and 3^rd years but not in 1^st year. (Total number of students is 500).