160 stickers are in 3 bags.
The first bag has 4 times as many stickers as the second bag.
The third bag is 20 less than the second bag.
How many less stickers are there in the second bag and the third bag than in the first bag?
Choose the bag with the least stickers to be 1 u.

Number of stickers in the third bag = 1 u
Number of stickers in the second bag = 1 u + 20
Number of stickers in the first bag = 4 x (1 u + 20) = 4 u + 80

Total number of stickers
= 4 u + 80 + 1 u + 20 + 1 u
= 4 u + 1 u + 1 u + 80 + 20
= 6 u + 100

6 u + 100 = 160
6 u = 160 - 100
6 u = 60

1 u = 60 ÷ 6 = 10

Number of less stickers in the second bag and third bag than the first bag
= (4 u + 80) - (1 u + 20 + 1 u)
= (4 u + 80) - (2 u + 20)
= 4 u - 2 u  + 80 - 20
= 2 u + 60
= 2 x 10 + 60
= 20 + 60
= 80

Answer(s): 80