Decimal P6

Timothy wants to buy a skateboard.It costs $17.25.Every week he saves $1.20 more than the week before.After saving for a number of weeks,he bought the skateboard. a)What is the least number of weeks he needs to save enough to buy the skateboard? b)How much of his savings did he have left after buying the skateboard?


Wk 1 --> $1.20

Wk 2 --> 1.20 + 1.20 x 2 --> $3.60

Wk 3 --> $3.60 + 1.20 x 3 = $7.20

Wk 4 --> $7.20 + 1.20 x 4 --> $12.00

Wk 5 --> 12.00 + 1.20 x 5 = $18.00 > $17.25

a) The least number of weeks he needs to save enough to buy the skateboard is 5.


18.00 - 17.25 = $0.75

b) He has $0.75 left.