Can someone plz help me with my whole homework?
 1.The original price is $20. The Percent of Discount is 20%. What is the sale price?
 2.The original price is $95. The Percent of Discount is 35%. What is the sale price?
 3.The Percent of Discount is 75%. The sale price is $55.50. What is the original price?
 4.The Percent of Discount is 40%. The sale price is $78. What is the original price?
 5.Find the selling price. The cost to store: $20. The markup: 15%.
 6.Find the selling price. The cost to store: $56. The markup: 80%.
 7.Find the selling price. The cost to store: $110. The markup: 140%.
 8.A store buys an item for $10. To earn a profit of $25, what percent does the store need to markup the item?
 9.An account earns simple interest. Find the interest earned.
 $400 at 7% for 3 years
 10.An account earns simple interest. Find the balance of the account.
 $400 at 7% for 3 years
 11.An account earns simple interest. Find the interest earned.
 $1200 at 5.6% for 4 years
 12.An account earns simple interest. Find the balance of the account.
 $1200 at 5.6% for 4 years
 13.Find the annual interest rate. 
 I = $18, P = $200, t = 18 months
 14.Find the annual interest rate. 
 I = $310, P = $1000, t = 5 years
 15.Find the amount of time. 
 I = $60, P = $750, r = 4%
 16.Find the amount of time. 
 I = $825, P = $72500, r = 5.5%
 17.You put $500 in a savings account. The account earns $15.75 simple interest in 6 months. What is the annual interest rate?