Ken saved $10 each day and Rachel saved $
w more than Ken each day. After 4 weeks, they were still short of $31 to buy a hi-fi system.
- How much did the hi-fi system cost? Express your answer in terms of w.
- If w = $13, how much did the hi-fi system cost?
(a)
Amount Ken saved per day = $10
Amount Rachel saved per day = $(10 +
w)
Total amount both saved per day
= 10 + 10 +
w = $(20 +
w)
Number of days in 4 weeks
= 4 x 7
= 28
Total both saved in 4 weeks
= 28(20 +
w)
= 28 x 20 + 28 x
w = $(560 + 28
w)
Cost of the hi-fi system
= 560 + 28
w + 31
= 560 + 31 + 28
w= $(591 + 28
w)
(b)
If
w = $13,
Cost of the hi-fi system
= 591 + 28 x 13
= 591 + 364
= $955
Answer(s): (a) $(591 + 28
w) or $(28
w + 591); (b) $955
