1 bead costs $6.
For every 10 beads bought, a discount of $5 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 6 - 5
= 60 - 5
= $55
(b)
Number of beads that do not belong to a set
= 13 ÷ 10
= 1 r 3
Cost of the 3 extra beads
= 3 x 6
= $18
Cost of 13 beads
= 55 + 18
= $73
(c)
Number of sets of 10 beads
= 39 ÷ 10
= 3 r 9
Cost of 30 beads
= 3 x 55
= $165
Cost of 9 beads
= 9 x 6
= $54
Cost of 39 beads
= 165 + 54
= $219
Answer(s): (a) $55; (b) $73; (c) $219