1. The towns population increased from 80,000 to 90,000 in ten years. What was the percent of increase? I didn't understand this one.

Question

2. A $15 item on sale for $12 is marked down what percent? 20%
3. If Jenna buys and item for 40% off the regular price, will she pay more or less than half the price? Less than
4. If Jenna saves $20 buying an item for 40% off the regular price, then what were the regular price and the sales price? Regular price is $50 and sales price is $30
This is what I got. Can someone please check this and if it's wrong please tell me my mistake and how to fix it. The answer will be helpful to make sure I get it right but please put in how to actually fix it. I really didn't understand this lesson

Answer 1

1.
90,000 - 80,000 = 10,000
100(10,000 / 80,000) = 12.5% increase

2. Yes

3. No

4. Yes