Caden saved $10 each day and Cathy saved $
c more than Caden each day. After 4 weeks, they were still short of $31 to buy a stereo system.
- How much did the stereo system cost? Express your answer in terms of c.
- If c = $7, how much did the stereo system cost?
(a)
Amount Caden saved per day = $10
Amount Cathy saved per day = $(10 +
c)
Total amount both saved per day
= 10 + 10 +
c = $(20 +
c)
Number of days in 4 weeks
= 4 x 7
= 28
Total both saved in 4 weeks
= 28(20 +
c)
= 28 x 20 + 28 x
c = $(560 + 28
c)
Cost of the stereo system
= 560 + 28
c + 31
= 560 + 31 + 28
c= $(591 + 28
c)
(b)
If
c = $7,
Cost of the stereo system
= 591 + 28 x 7
= 591 + 196
= $787
Answer(s): (a) $(591 + 28
c) or $(28
c + 591); (b) $787
