Final answer:
Derek played in 61% of the games, so he earned a varsity letter on the baseball team.
Step-by-step explanation:
To earn a varsity letter on the baseball team, a student must play in 60% of the games. Derek played in 11 out of 18 baseball games. To determine if he earned a varsity letter, we need to calculate the percentage of games he played.
First, we divide the number of games Derek played (11) by the total number of games (18):
11/18 = 0.61
Multiplying this value by 100, we find that Derek played in approximately 61% of the games. Since 61% is greater than the required 60%, Derek earned a varsity letter on the baseball team.