# Math Help - Interest vs Discount problem

1. ## Interest vs Discount problem

In an effective quarterly rate $k$ of compound interest, 1000 accumulates to 2500 in 20 years. What would be the value after $20$ years if the initial deposit of $1000$ had grown under an effective quarterly rate $k$ of compound discount?

2. Get k by solving: 1000(1 + k)^80 = 2500

I don't know what you mean by "discount"; negative k ?

3. Originally Posted by Wilmer
Get k by solving: 1000(1 + k)^80 = 2500

I don't know what you mean by "discount"; negative k ?
Discount is related to interest by $(1+{i})(1-{d})=1$ but thanks. I understand what the problem is asking now.