Trayvon enters a competition to guess how many balls are in a barrel. Trayvon’s guess is 63 balls. The actual number of balls is 60. What is the percent error of Trayvon’s guess?

In a small section of a stadium there are 40 spectators watching a game between the cook islands and fiji. they all support at least one of the two teams. 25 spectators support the cook islands and 16 of these support both teams. how many support only fiji?