1 bead costs $9.
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 28 beads cost?
(a)
Cost of every 10 beads
= 10 x 9 - 5
= 90 - 5
= $85
(b)
Number of beads that do not belong to a set
= 15 ÷ 10
= 1 r 5
Cost of the 5 extra beads
= 5 x 9
= $45
Cost of 15 beads
= 85 + 45
= $130
(c)
Number of sets of 10 beads
= 28 ÷ 10
= 2 r 8
Cost of 20 beads
= 2 x 85
= $170
Cost of 8 beads
= 8 x 9
= $72
Cost of 28 beads
= 170 + 72
= $242
Answer(s): (a) $85; (b) $130; (c) $242