A sticker, a marble and a bead costs $8.80 altogether.
The sticker costs $1.50 less than the marble.
The bead costs $3.40 more than the marble.
How much do 5 beads cost?
Choose the cheapest item to be 1 u.
The sticker costs $1.50 less than the marble.
The cheapest item is the sticker.

Cost of the sticker = 1 u
Cost of the marble = 1 u + 1.50
Cost of the bead = 1 u + 1.50 + 3.40 = 1 u + 4.90

Total cost of the sticker, the marble and the bead
= 1 u + 1 u + 1.50 + 1 u + 4.90
= 1 u + 1 u + 1 u + 1.50 + 4.90
= 3 u + 6.4

3 u + 6.40 = 8.80
3 u = 8.80 - 6.40
3 u = 2.40

1 u = 2.40 ÷ 3 = 0.80

Cost of 5 beads
= 5 x (1 u + 4.90)
= 5 x (0.80 + 4.90)
= 5 x 5.70
= $28.50

Answer(s): $28.50