1 bead costs $7.
For every 10 beads bought, a discount of $4 is given.
- How much do 10 beads cost?
- How much do 12 beads cost?
- How much do 21 beads cost?
(a)
Cost of every 10 beads
= 10 x 7 - 4
= 70 - 4
= $66
(b)
Number of beads that do not belong to a set
= 12 ÷ 10
= 1 r 2
Cost of the 2 extra beads
= 2 x 7
= $14
Cost of 12 beads
= 66 + 14
= $80
(c)
Number of sets of 10 beads
= 21 ÷ 10
= 2 r 1
Cost of 20 beads
= 2 x 66
= $132
Cost of 1 beads
= 1 x 7
= $7
Cost of 21 beads
= 132 + 7
= $139
Answer(s): (a) $66; (b) $80; (c) $139