Adam pays $14.60 for 3 beads and 4 marbles.
A bead costs $1.60 more than 1 marble.
What is the cost of 4 beads and 3 marbles?
Choose the cheaper item to be 1 u.
1 bead costs $1.60 more than 1 marble.
The cheaper item is the marble.

Cost of the marble = 1 u
Cost of the bead = 1 u + 1.60

Cost of 3 beads = 3 x (1 u + 1.60) = 3 u + 4.80
Cost of 4 marbles = 4 u

Total cost of 3 beads and 4 marbles
= 3 u + 4.80 + 4 u
= 3 u + 4 u + 4.80
= 7 u + 4.80

7 u + 4.80 = 14.60
7 u = 14.60 - 4.80
7 u = 9.80

1 u = 9.80 ÷ 7 = 1.40

Cost of 4 beads and 3 marbles
= 4 x (1 u + 1.60) + 3 u
= 4 u + 6.40 + 3 u
= 4 u + 3 u + 6.40
= 7 u + 6.40
= 7 x 1.40 + 6.40
= 9.80 + 6.40
= $16.20

Answer(s): $16.20