Question

Lianne is saving to buy a DVD player that costs 2 1\2 times her weekly allowance. If she spends 3\4 of her allowance on other things, how long will she take to save the money for the DVD player?

Answer 1

She will take 10 weeks to save the money for the DVD player

Explanation:

Let w = Lianne's weekly allowance.

The DVD player costs 2 1/2 times her weekly allowance, thus

DVD cost = 5/2w

She gets w every week but spends 3/4w on other things, thus the remaining money is

Weekly savings =w - 3/4w = 1/4w

To know the number of weeks needed, we divide the DVD cost by the weekly savings:

`\displaystyle N = ((5)/(2))/((1)/(4))`

Operating:

`\displaystyle N = (5)/(2)*(4)/(1)`

N = 10

She will take 10 weeks to save the money for the DVD player