PATTERNS, FUR1 2009 VCAA 2 MC

Each week a young boy saves an amount of his pocket money. The amount saved forms part of an arithmetic sequence. The table shows the amounts he saves in weeks 1 to 3.

If he continues to save in this way, the amount he will save in week eight is

A. `$1.45`

B. `$1.60`

C. `$1.65`

D. `$7.40`

E. `$8.00`

Show Answers Only

`A`

Show Worked Solution

`text(Sequence is 0.40, 0.55, 0.70, …)`

`text(AP where)\ \ \ a`	`= 0.40`
`d`	`= 0.55 – 0.40 = 0.15`

`T_n`	`= a + (n – 1) \ d`
`:.T_8`	`= 0.40 + (8 – 1) \ 0.15`
	`= 0.40 + 1.05`
	`= 1.45`

`=> A`