Please help with all. Find the simple interest rate to the nearest cent: $1,050, 4.5%, 2 years

Find the simple interest rate to the nearest cent: $500, 3.75%, 4 months

Find the simple interest rate to the nearest cent: $1,000, 7%, 2 years

Find the simple interest rate to the nearest cent: $2,700, 8.2%, 3 months

Leon charged $75 at an interest rate of 12.5%. How much will Leon have to pay after one month if he makes no payments?

What is the simple interest earned on $900 for 9 months at 2.9%?

What is the simple interest earned on $2,500 for 18 months at 3.1%?