Problem link : http://codeforces.com/problemset/problem/750/A
This problem requires you to count how many problems Limak can do in 240 – k minutes.
One way I can think of is to manually count how many minutes Limak need to do 1 problem – 10 problems (t1 – t10), and then based on the time left (240 -k), find how many problems he can solve. (Answer is i where ti < 240 -k < ti+1)
Or you can always simulate them. I did simulation and everything is smooth as silk.