The table shows how much Jade saves daily. For each subsequent day, she saves $5 more than the previous day.
- How much will Jade save on Day 10?
- On which day will Jade save $185?
- How much savings will Jade have in total by the day found in part (b)?
(a)
Pattern for the amount saved
Day 1: 1 x 5 + 10 = $15
Day 2: 2 x 5 + 10 = $20
Day 3: 3 x 5 + 10 = $25
Day 4: 4 x 5 + 10 = $30
Formula
Amount saved = Day Number x 5 + 10
Amount saved on Day 10
= 10 x 5 + 10
= $60
(b)
Number of days that Jade takes to save $185
= (185 - 10) ÷ 5
= 175 ÷ 5
= 35
(c)
Total savings that Jade saves by Day 35
= 15 + 20 + ... + 180 + 185
= (15 + 185) x (35 ÷ 2)
= 200 x 17.5
= $3500
Answer(s): (a) $60; (b) 35; (c) $3500
