Lui saved $12 each day and Fanny saved $
f more than Lui each day. After 2 weeks, they were still short of $28 to buy a mobile phone.
- How much did the mobile phone cost? Express your answer in terms of f.
- If f = $3, how much did the mobile phone cost?
(a)
Amount Lui saved per day = $12
Amount Fanny saved per day = $(12 +
f)
Total amount both saved per day
= 12 + 12 +
f = $(24 +
f)
Number of days in 2 weeks
= 2 x 7
= 14
Total both saved in 2 weeks
= 14(24 +
f)
= 14 x 24 + 14 x
f = $(336 + 14
f)
Cost of the mobile phone
= 336 + 14
f + 28
= 336 + 28 + 14
f= $(364 + 14
f)
(b)
If
f = $3,
Cost of the mobile phone
= 364 + 14 x 3
= 364 + 42
= $406
Answer(s): (a) $(364 + 14
f) or $(14
f + 364); (b) $406
