The table shows how much Jane saves daily. For each subsequent day, she saves $4 more than the previous day.
- How much will Jane save on Day 10?
- On which day will Jane save $134?
- How much savings will Jane have in total by the day found in part (b)?
(a)
Pattern for the amount saved
Day 1: 1 x 4 + 10 = $14
Day 2: 2 x 4 + 10 = $18
Day 3: 3 x 4 + 10 = $22
Day 4: 4 x 4 + 10 = $26
Formula
Amount saved = Day Number x 4 + 10
Amount saved on Day 10
= 10 x 4 + 10
= $50
(b)
Number of days that Jane takes to save $134
= (134 - 10) ÷ 4
= 124 ÷ 4
= 31
(c)
Total savings that Jane saves by Day 31
= 14 + 18 + ... + 130 + 134
= (14 + 134) x (31 ÷ 2)
= 148 x 15.5
= $2294
Answer(s): (a) $50; (b) 31; (c) $2294
