A football team won 10 matches out of the total number of matches they played. If their win percentage was 40%, then how many matches did they play in all?

Let the total number of matches played by the football team be x.
No. of matches won = 10
∴ Win percent = (No. of matches won / Total no. of matches played) * 100
∴ 40 = (10 / x) * 100
∴ 40x = 1000
∴ x = 1000 / 40
∴ x = 25
Therefore, the total number of matches played is 25.