1 bead costs $3.
For every 10 beads bought, a discount of $5 is given.
- How much do 10 beads cost?
- How much do 18 beads cost?
- How much do 31 beads cost?
(a)
Cost of every 10 beads
= 10 x 3 - 5
= 30 - 5
= $25
(b)
Number of beads that do not belong to a set
= 18 ÷ 10
= 1 r 8
Cost of the 8 extra beads
= 8 x 3
= $24
Cost of 18 beads
= 25 + 24
= $49
(c)
Number of sets of 10 beads
= 31 ÷ 10
= 3 r 1
Cost of 30 beads
= 3 x 25
= $75
Cost of 1 beads
= 1 x 3
= $3
Cost of 31 beads
= 75 + 3
= $78
Answer(s): (a) $25; (b) $49; (c) $78