2200 stickers are in 3 bags.
The 3rd bag has 600 stickers more than the total number of stickers in the 1st and 2nd bags.
The 2nd bag has 3 times as many stickers as the 1st bag.
How many stickers does the 3rd bag contain?
Choose the bag with the least stickers to be 1 u.

Number of stickers in the 1st bag = 1 u
Number of stickers in the 2nd bag = 3 u

Number of stickers in the 1st bag and 2nd bag
= 1 u + 3 u
= 4 u

Number of stickers in the 3rd bag = 4 u + 600

Total number of stickers
= 1 u + 3 u + 4 u + 600
= 8 u + 600

8 u + 600 = 2200
8 u = 2200 - 600
8 u = 1600

1 u = 1600 ÷ 8 = 200

Number of stickers in the 3rd bag
= 4 u + 600
= 4 x 200 + 600
= 800 + 600
= 1400

Answer(s): 1400