1 marble costs $5.
For every 10 marbles bought, a discount of $6 is given.
- How much do 10 marbles cost?
- How much do 14 marbles cost?
- How much do 25 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
= 14 ÷ 10
= 1 r 4
Cost of the 4 extra marbles
= 4 x 5
= $20
Cost of 14 marbles
= 44 + 20
= $64
(c)
Number of sets of 10 marbles
= 25 ÷ 10
= 2 r 5
Cost of 20 marbles
= 2 x 44
= $88
Cost of 5 marbles
= 5 x 5
= $25
Cost of 25 marbles
= 88 + 25
= $113
Answer(s): (a) $44; (b) $64; (c) $113