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

3 x 9X = 1x( 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!