1. Alan got 80% in his math test, Jorden got one-fifth more, what is the mark of Jorden?
2. The salary of a doctor is increased by 25%. The new salary is $8000. What is the original salary?
3. Increase 200 by 10% and then decrease by 20%. Find the new number.
4. The salary of a doctor is increased by 20%. By what percent should the new salary be reduced in order to restore the original salary?
5. Steph took out a compound interest loan that charges 2.5% interest annually. If her original loan amount was for $60,000 and she is paying off the loan over 2 years, how much will she pay altogether? What is the interest?