1 bead costs $7.
For every 10 beads bought, a discount of $7 is given.
- How much do 10 beads cost?
- How much do 15 beads cost?
- How much do 28 beads cost?
(a)
Cost of every 10 beads
= 10 x 7 - 7
= 70 - 7
= $63
(b)
Number of beads that do not belong to a set
= 15 ÷ 10
= 1 r 5
Cost of the 5 extra beads
= 5 x 7
= $35
Cost of 15 beads
= 63 + 35
= $98
(c)
Number of sets of 10 beads
= 28 ÷ 10
= 2 r 8
Cost of 20 beads
= 2 x 63
= $126
Cost of 8 beads
= 8 x 7
= $56
Cost of 28 beads
= 126 + 56
= $182
Answer(s): (a) $63; (b) $98; (c) $182