Jack saved $10 each day and Xuan saved $
r more than Jack each day. After 4 weeks, they were still short of $32 to buy a computer.
- How much did the computer cost? Express your answer in terms of r.
- If r = $15, how much did the computer cost?
(a)
Amount Jack saved per day = $10
Amount Xuan saved per day = $(10 +
r)
Total amount both saved per day
= 10 + 10 +
r = $(20 +
r)
Number of days in 4 weeks
= 4 x 7
= 28
Total both saved in 4 weeks
= 28(20 +
r)
= 28 x 20 + 28 x
r = $(560 + 28
r)
Cost of the computer
= 560 + 28
r + 32
= 560 + 32 + 28
r= $(592 + 28
r)
(b)
If
r = $15,
Cost of the computer
= 592 + 28 x 15
= 592 + 420
= $1012
Answer(s): (a) $(592 + 28
r) or $(28
r + 592); (b) $1012
