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?