1 marble costs $8.
For every 10 marbles bought, a discount of $6 is given.
- How much do 10 marbles cost?
- How much do 15 marbles cost?
- How much do 34 marbles cost?
(a)
Cost of every 10 marbles
= 10 x 8 - 6
= 80 - 6
= $74
(b)
Number of marbles that do not belong to a set
= 15 ÷ 10
= 1 r 5
Cost of the 5 extra marbles
= 5 x 8
= $40
Cost of 15 marbles
= 74 + 40
= $114
(c)
Number of sets of 10 marbles
= 34 ÷ 10
= 3 r 4
Cost of 30 marbles
= 3 x 74
= $222
Cost of 4 marbles
= 4 x 8
= $32
Cost of 34 marbles
= 222 + 32
= $254
Answer(s): (a) $74; (b) $114; (c) $254