The table shows how much Hilda saves daily. For each subsequent day, she saves $8 more than the previous day.
- How much will Hilda save on Day 8?
- On which day will Hilda save $50?
- How much savings will Hilda 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 Hilda takes to save $50
= (50 - 10) ÷ 8
= 40 ÷ 8
= 5
(c)
Total savings that Hilda saves by Day 5
= 18 + 26 + ... + 42 + 50
= (18 + 50) x (5 ÷ 2)
= 68 x 2.5
= $170
Answer(s): (a) $74; (b) 5; (c) $170