Simple interest: find the principal

Use interest = principal × rate × time, with the rate as a percent per year.

1. A deposit at 5% simple interest per year earns $20 in 2 years. How much was deposited?
2. A deposit at 2% simple interest per year earns $24 in 2 years. How much was deposited?
3. A deposit at 10% simple interest per year earns $80 in 2 years. How much was deposited?
4. A deposit at 5% simple interest per year earns $20 in 1 year. How much was deposited?
5. A deposit at 2% simple interest per year earns $56 in 4 years. How much was deposited?
6. A deposit at 6% simple interest per year earns $72 in 4 years. How much was deposited?
7. A deposit at 5% simple interest per year earns $140 in 2 years. How much was deposited?
8. A deposit at 6% simple interest per year earns $48 in 1 year. How much was deposited?
9. A deposit at 3% simple interest per year earns $435 in 5 years. How much was deposited?
10. A deposit at 2% simple interest per year earns $104 in 2 years. How much was deposited?
11. A deposit at 4% simple interest per year earns $600 in 5 years. How much was deposited?
12. A deposit at 5% simple interest per year earns $625 in 5 years. How much was deposited?
13. A deposit at 9% simple interest per year earns $1935 in 5 years. How much was deposited?
14. A deposit at 2% simple interest per year earns $240 in 3 years. How much was deposited?
15. A deposit at 3% simple interest per year earns $297 in 3 years. How much was deposited?
16. A deposit at 2% simple interest per year earns $440 in 5 years. How much was deposited?
17. A deposit at 10% simple interest per year earns $2850 in 5 years. How much was deposited?
18. A deposit at 5% simple interest per year earns $360 in 6 years. How much was deposited?
19. A deposit at 2% simple interest per year earns $296 in 2 years. How much was deposited?
20. A deposit at 9% simple interest per year earns $378 in 2 years. How much was deposited?