Tim saved $10 each day and Cathy saved $
a more than Tim each day. After 4 weeks, they were still short of $29 to buy a hi-fi system.
- How much did the hi-fi system cost? Express your answer in terms of a.
- If a = $19, how much did the hi-fi system cost?
(a)
Amount Tim saved per day = $10
Amount Cathy saved per day = $(10 +
a)
Total amount both saved per day
= 10 + 10 +
a = $(20 +
a)
Number of days in 4 weeks
= 4 x 7
= 28
Total both saved in 4 weeks
= 28(20 +
a)
= 28 x 20 + 28 x
a = $(560 + 28
a)
Cost of the hi-fi system
= 560 + 28
a + 29
= 560 + 29 + 28
a= $(589 + 28
a)
(b)
If
a = $19,
Cost of the hi-fi system
= 589 + 28 x 19
= 589 + 532
= $1121
Answer(s): (a) $(589 + 28
a) or $(28
a + 589); (b) $1121
