3. Teacher Wang has 45 candies, and he decides to eat some every day. Since the candies are very delicious, starting from the second day, the number of candies he eats each day is 3 more than the previous day, and he finishes all the candies in 5 days. So, how many candies did Teacher Wang eat on the second day? ( )
【Analysis】Calculation, Arithmetic Sequence
Since the number of candies eaten each day is 3 more than the previous day, it forms an arithmetic sequence with a common difference of 3, and there are 5 terms. Directly find the middle term, the third day $45 \div 5=9$, so the second day is $9-3=6$ (candies).