Caden saved $10 each day and Mary saved $
f more than Caden each day. After 6 weeks, they were still short of $30 to buy a hi-fi system.
- How much did the hi-fi system cost? Express your answer in terms of f.
- If f = $8, how much did the hi-fi system cost?
(a)
Amount Caden saved per day = $10
Amount Mary saved per day = $(10 +
f)
Total amount both saved per day
= 10 + 10 +
f = $(20 +
f)
Number of days in 6 weeks
= 6 x 7
= 42
Total both saved in 6 weeks
= 42(20 +
f)
= 42 x 20 + 42 x
f = $(840 + 42
f)
Cost of the hi-fi system
= 840 + 42
f + 30
= 840 + 30 + 42
f= $(870 + 42
f)
(b)
If
f = $8,
Cost of the hi-fi system
= 870 + 42 x 8
= 870 + 336
= $1206
Answer(s): (a) $(870 + 42
f) or $(42
f + 870); (b) $1206
