The table shows how much Raeann saves daily. For each subsequent day, she saves $9 more than the previous day.
- How much will Raeann save on Day 6?
- On which day will Raeann save $181?
- How much savings will Raeann have in total by the day found in part (b)?
(a)
Pattern for the amount saved
Day 1: 1 x 9 + 10 = $19
Day 2: 2 x 9 + 10 = $28
Day 3: 3 x 9 + 10 = $37
Day 4: 4 x 9 + 10 = $46
Formula
Amount saved = Day Number x 9 + 10
Amount saved on Day 6
= 6 x 9 + 10
= $64
(b)
Number of days that Raeann takes to save $181
= (181 - 10) ÷ 9
= 171 ÷ 9
= 19
(c)
Total savings that Raeann saves by Day 19
= 19 + 28 + ... + 172 + 181
= (19 + 181) x (19 ÷ 2)
= 200 x 9.5
= $1900
Answer(s): (a) $64; (b) 19; (c) $1900