Question 1: 20+20/3 (integer) +20/6 (integer) =20+6+3=29 bottles.

Question 2: 1 yuan 1 bottle, 1 bottle with 3 bottles, 1 bottle with 6 caps. We can know that six dollars can buy nine bottles.

We need 60 bottles now.

60/9=6, the remainder is 6 bottles.

6 yuan x6=36

Six bottles need 5 yuan.

So 60 bottles need 4 1 yuan.