1 bead costs $9.
For every 10 beads bought, a discount of $3 is given.
- How much do 10 beads cost?
- How much do 18 beads cost?
- How much do 25 beads cost?
(a)
Cost of every 10 beads
= 10 x 9 - 3
= 90 - 3
= $87
(b)
Number of beads that do not belong to a set
= 18 ÷ 10
= 1 r 8
Cost of the 8 extra beads
= 8 x 9
= $72
Cost of 18 beads
= 87 + 72
= $159
(c)
Number of sets of 10 beads
= 25 ÷ 10
= 2 r 5
Cost of 20 beads
= 2 x 87
= $174
Cost of 5 beads
= 5 x 9
= $45
Cost of 25 beads
= 174 + 45
= $219
Answer(s): (a) $87; (b) $159; (c) $219