1 marble costs $6.
For every 10 marbles bought, a discount of $4 is given.
- How much do 10 marbles cost?
- How much do 17 marbles cost?
- How much do 34 marbles cost?
(a)
Cost of every 10 marbles
= 10 x 6 - 4
= 60 - 4
= $56
(b)
Number of marbles that do not belong to a set
= 17 ÷ 10
= 1 r 7
Cost of the 7 extra marbles
= 7 x 6
= $42
Cost of 17 marbles
= 56 + 42
= $98
(c)
Number of sets of 10 marbles
= 34 ÷ 10
= 3 r 4
Cost of 30 marbles
= 3 x 56
= $168
Cost of 4 marbles
= 4 x 6
= $24
Cost of 34 marbles
= 168 + 24
= $192
Answer(s): (a) $56; (b) $98; (c) $192