1 bead costs $9.
For every 10 beads bought, a discount of $4 is given.
- How much do 10 beads cost?
- How much do 14 beads cost?
- How much do 21 beads cost?
(a)
Cost of every 10 beads
= 10 x 9 - 4
= 90 - 4
= $86
(b)
Number of beads that do not belong to a set
= 14 ÷ 10
= 1 r 4
Cost of the 4 extra beads
= 4 x 9
= $36
Cost of 14 beads
= 86 + 36
= $122
(c)
Number of sets of 10 beads
= 21 ÷ 10
= 2 r 1
Cost of 20 beads
= 2 x 86
= $172
Cost of 1 beads
= 1 x 9
= $9
Cost of 21 beads
= 172 + 9
= $181
Answer(s): (a) $86; (b) $122; (c) $181