Buying retro CDs and DVDs

This task is about working out costs.
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Mr Toimata was buying some retro CDs and DVDs.

Question 1Change answer

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a)  If each CD cost $12.65, how much will a box of 8 Sing-along CDs cost him?
     $ 

Question 1Change answer

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b)  If each CD costs $11.65, how much will a set of 6 Jazz CDs cost him?
     $ 

Question 1Change answer

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c)  If a set of 4 aerobic DVDs cost $54.60, how much does each DVD cost?
     $