1 marble costs $5.
For every 10 marbles bought, a discount of $6 is given.
- How much do 10 marbles cost?
- How much do 12 marbles cost?
- How much do 32 marbles cost?
(a)
Cost of every 10 marbles
= 10 x 5 - 6
= 50 - 6
= $44
(b)
Number of marbles that do not belong to a set
= 12 ÷ 10
= 1 r 2
Cost of the 2 extra marbles
= 2 x 5
= $10
Cost of 12 marbles
= 44 + 10
= $54
(c)
Number of sets of 10 marbles
= 32 ÷ 10
= 3 r 2
Cost of 30 marbles
= 3 x 44
= $132
Cost of 2 marbles
= 2 x 5
= $10
Cost of 32 marbles
= 132 + 10
= $142
Answer(s): (a) $44; (b) $54; (c) $142