1 marble costs $8.
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 22 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
= 14 ÷ 10
= 1 r 4
Cost of the 4 extra marbles
= 4 x 8
= $32
Cost of 14 marbles
= 74 + 32
= $106
(c)
Number of sets of 10 marbles
= 22 ÷ 10
= 2 r 2
Cost of 20 marbles
= 2 x 74
= $148
Cost of 2 marbles
= 2 x 8
= $16
Cost of 22 marbles
= 148 + 16
= $164
Answer(s): (a) $74; (b) $106; (c) $164