There are 85 stickers in Container R and 25 stickers in Container S.
Some stickers are transferred from Container R to Container S.
Container S has 20 more stickers than Container R.
How many stickers are transferred from Container R to Container S?

	Container R	Container S
Before	85	25
Change	- ?	+ ?
After	1 u	1 u + 20

Total number of stickers
= 85 + 25
= 110

In the end
Total number of stickers = 1 u + 1 u + 20 = 2 u + 20

The total number of stickers at first and in the end remains unchanged.

2 u + 20 = 110
2 u = 110 - 20 = 90

1 u = 90 ÷ 2 = 45

Number of stickers that are transferred from Container R to Container S
= Number of stickers in Container R at first - Number of stickers in Container R in the end
= 85 - 45
= 40

Answer(s): 40