1 bead costs $7.
For every 10 beads bought, a discount of $3 is given.
- How much do 10 beads cost?
- How much do 15 beads cost?
- How much do 23 beads cost?
(a)
Cost of every 10 beads
= 10 x 7 - 3
= 70 - 3
= $67
(b)
Number of beads that do not belong to a set
= 15 ÷ 10
= 1 r 5
Cost of the 5 extra beads
= 5 x 7
= $35
Cost of 15 beads
= 67 + 35
= $102
(c)
Number of sets of 10 beads
= 23 ÷ 10
= 2 r 3
Cost of 20 beads
= 2 x 67
= $134
Cost of 3 beads
= 3 x 7
= $21
Cost of 23 beads
= 134 + 21
= $155
Answer(s): (a) $67; (b) $102; (c) $155