Tommy saved $9 each day and Penelope saved $
p more than Tommy 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 p.
- If p = $10, how much did the hi-fi system cost?
(a)
Amount Tommy saved per day = $9
Amount Penelope saved per day = $(9 +
p)
Total amount both saved per day
= 9 + 9 +
p = $(18 +
p)
Number of days in 4 weeks
= 4 x 7
= 28
Total both saved in 4 weeks
= 28(18 +
p)
= 28 x 18 + 28 x
p = $(504 + 28
p)
Cost of the hi-fi system
= 504 + 28
p + 31
= 504 + 31 + 28
p= $(535 + 28
p)
(b)
If
p = $10,
Cost of the hi-fi system
= 535 + 28 x 10
= 535 + 280
= $815
Answer(s): (a) $(535 + 28
p) or $(28
p + 535); (b) $815
