1 bead costs $8.
For every 10 beads bought, a discount of $3 is given.
- How much do 10 beads cost?
- How much do 13 beads cost?
- How much do 39 beads cost?
(a)
Cost of every 10 beads
= 10 x 8 - 3
= 80 - 3
= $77
(b)
Number of beads that do not belong to a set
= 13 ÷ 10
= 1 r 3
Cost of the 3 extra beads
= 3 x 8
= $24
Cost of 13 beads
= 77 + 24
= $101
(c)
Number of sets of 10 beads
= 39 ÷ 10
= 3 r 9
Cost of 30 beads
= 3 x 77
= $231
Cost of 9 beads
= 9 x 8
= $72
Cost of 39 beads
= 231 + 72
= $303
Answer(s): (a) $77; (b) $101; (c) $303