1 bead costs $4.
For every 10 beads bought, a discount of $5 is given.
- How much do 10 beads cost?
- How much do 15 beads cost?
- How much do 31 beads cost?
(a)
Cost of every 10 beads
= 10 x 4 - 5
= 40 - 5
= $35
(b)
Number of beads that do not belong to a set
= 15 ÷ 10
= 1 r 5
Cost of the 5 extra beads
= 5 x 4
= $20
Cost of 15 beads
= 35 + 20
= $55
(c)
Number of sets of 10 beads
= 31 ÷ 10
= 3 r 1
Cost of 30 beads
= 3 x 35
= $105
Cost of 1 beads
= 1 x 4
= $4
Cost of 31 beads
= 105 + 4
= $109
Answer(s): (a) $35; (b) $55; (c) $109