1 bead costs $8.
For every 10 beads bought, a discount of $4 is given.
- How much do 10 beads cost?
- How much do 18 beads cost?
- How much do 31 beads cost?
(a)
Cost of every 10 beads
= 10 x 8 - 4
= 80 - 4
= $76
(b)
Number of beads that do not belong to a set
= 18 ÷ 10
= 1 r 8
Cost of the 8 extra beads
= 8 x 8
= $64
Cost of 18 beads
= 76 + 64
= $140
(c)
Number of sets of 10 beads
= 31 ÷ 10
= 3 r 1
Cost of 30 beads
= 3 x 76
= $228
Cost of 1 beads
= 1 x 8
= $8
Cost of 31 beads
= 228 + 8
= $236
Answer(s): (a) $76; (b) $140; (c) $236