The table shows how much Tiffany saves daily. For each subsequent day, she saves $6 more than the previous day.
- How much will Tiffany save on Day 6?
- On which day will Tiffany save $118?
- How much savings will Tiffany have in total by the day found in part (b)?
(a)
Pattern for the amount saved
Day 1: 1 x 6 + 10 = $16
Day 2: 2 x 6 + 10 = $22
Day 3: 3 x 6 + 10 = $28
Day 4: 4 x 6 + 10 = $34
Formula
Amount saved = Day Number x 6 + 10
Amount saved on Day 6
= 6 x 6 + 10
= $46
(b)
Number of days that Tiffany takes to save $118
= (118 - 10) ÷ 6
= 108 ÷ 6
= 18
(c)
Total savings that Tiffany saves by Day 18
= 16 + 22 + ... + 112 + 118
= (16 + 118) x (18 ÷ 2)
= 134 x 9
= $1206
Answer(s): (a) $46; (b) 18; (c) $1206
