A club has played 40 knockout matches this season and has won 55% of them. Of its next 10 matches, how many must it win so that it ends up having won 60% of all 50 matches?

Wins so far = 55% of 40 = 22. To finish on 60% of 50 the club needs 30 wins, so it must win 30 - 22 = 8 of the next 10. 6 applies the target rate of 60% to the next 10 matches only, forgetting that the 40 already played drag the figure down. 5 reads the 5-percentage-point gap as 5 matches. 10 assumes every remaining match must be won, which overshoots - that would give 32 wins, or 64%.