1．Eleven members of the Middle School Math Club each paid the same amount for a guest speaker to talk about problem solving at their math club meeting.They paid their guest speaker $1A2.What is the missing digit A of this 3-digit number？（　　）
中學數(shù)學俱樂部的11名成員為請一位嘉賓講解他們數(shù)學俱樂部會議中的問題的解決方法而支付了相同的金額。他們支付給嘉賓講者的費用是$1A2。這個3位數(shù)中缺失的數(shù)字A是多少？（　?。?/div>

2．How many integers between 2020 and 2400 have four distinct digits ar-ranged in increasing order？（For example,2357 is one such integer.）（　?。?br />在2020年到2400年之間，有多少個整數(shù)的四個不同數(shù)字按升序排列？（例如，2357就是這樣的一個整數(shù)。）（　?。?/div>

3．將0，1，2，…，2016這2017個整數(shù)按順序圍成一圈，從0開始數(shù)，按“1，2，3”，“1，2，3“，…的次序，逢3留下，其余的數(shù)取走，則最后留下的數(shù)是 ．