Analysis: At first, soft candy accounted for 9/20, and then hard candy accounted for 1 1/20, which means that the ratio of soft candy to hard candy is 9: 1 1. After adding 16 hard candy, soft candy accounts for 1/4, and hard candy accounts for 3/4.

1-9/20= 1 1/20

9/20

：

1 1/20=9: 1 1

1- 1/4=3/4

1/4

：

3/4= 1:3

Solution: Suppose there are 9x soft sweets at the beginning, then there are 1 1x hard sweets.

9x:( 1 1x+ 16)= 1:3

three

x

9x= 1

x

( 1 1x+ 16)

27x= 1 1x+ 16

16x= 16

x= 1

9x=9

1 1x= 1 1

It turns out that this pile of candy has 9 soft sweets, 1 1 hard sweets.

Comments: The key to this problem is to convert scores into proportions. Assuming the unknown quantity, solve the equation, which is still very difficult for sixth-grade students.

I hope my answer can help you. If you don't understand, please ask.

Hope to adopt!