Lui saved $12 each day and Jane saved $
a more than Lui each day. After 2 weeks, they were still short of $31 to buy a mobile phone.
- How much did the mobile phone cost? Express your answer in terms of a.
- If a = $6, how much did the mobile phone cost?
(a)
Amount Lui saved per day = $12
Amount Jane saved per day = $(12 +
a)
Total amount both saved per day
= 12 + 12 +
a = $(24 +
a)
Number of days in 2 weeks
= 2 x 7
= 14
Total both saved in 2 weeks
= 14(24 +
a)
= 14 x 24 + 14 x
a = $(336 + 14
a)
Cost of the mobile phone
= 336 + 14
a + 31
= 336 + 31 + 14
a= $(367 + 14
a)
(b)
If
a = $6,
Cost of the mobile phone
= 367 + 14 x 6
= 367 + 84
= $451
Answer(s): (a) $(367 + 14
a) or $(14
a + 367); (b) $451