The table shows how much Gem saves daily. For each subsequent day, she saves $8 more than the previous day.
- How much will Gem save on Day 8?
- On which day will Gem save $114?
- How much savings will Gem have in total by the day found in part (b)?
(a)
Pattern for the amount saved
Day 1: 1 x 8 + 10 = $18
Day 2: 2 x 8 + 10 = $26
Day 3: 3 x 8 + 10 = $34
Day 4: 4 x 8 + 10 = $42
Formula
Amount saved = Day Number x 8 + 10
Amount saved on Day 8
= 8 x 8 + 10
= $74
(b)
Number of days that Gem takes to save $114
= (114 - 10) ÷ 8
= 104 ÷ 8
= 13
(c)
Total savings that Gem saves by Day 13
= 18 + 26 + ... + 106 + 114
= (18 + 114) x (13 ÷ 2)
= 132 x 6.5
= $858
Answer(s): (a) $74; (b) 13; (c) $858
