What's the difference between simple interest and compound interest?

I want to invest in a company. They promised me high returns but I don't see how they are going to make so much money. Should I invest?

I want to open a savings account. The bank offers me a 10% interest rate. I deposit 1000$ for 2 (!) years. Using a compound interest, calculate how much money you will have by the end of your 2nd year.

What's the formula of simple interest?

What is interest rate?

Which interest formula do banks normally use - simple interest or compound interest?

What's the formula of compound interest?

In which situations you may use simple or compound interest?

If you are offered a 50% interest rate for your savings account (deposit) - what will you do?

I want to take a loan - 500$. The bank offered a 7% loan, but I have to return money in 1 year. How much money will I return in total?